Thornycroft Instrument Panel

[Tracy D'arth]

23 minutes ago, christophert said:

I'm wondering if changing the sender's is first port of call. Chances of both going together is slim but worth a pop.The rev counter failed after the gauges behaved as though they were shorting, so possibly a separate issue

I'm wondering if it's worth paying to have a new wiring harness fitted, as the electrics do look a mess

Going to see if someone local can test panel to rule it out, then maybe pay to have new wiring harness fitted as wiring very untidy and messy

A new wiring loom will cost you.

 

You can rule out the senders, temperature and oil pressure, by disconnecting the wires at the engine sensors one at a time. The requisite gauge will drop to zero if the sensor is faulty. But you will find that it makes no difference because it is the negative wiring to the clocks that is missing.

[Tony Brooks]

1 hour ago, christophert said:

'm wondering if changing the sender's is first port of call. Chances of both going together is slim but worth a pop.The rev counter failed after the gauges behaved as though they were shorting, so possibly a separate issue

 

But the rev counter does not have a sender as such so if that has stopped working it either means the alternator has failed or it is something else and all your symptoms indicate it is the lack of a negative to the gauges. No negative would affect all three instruments you listed.

 

1 hour ago, christophert said:

Going to see if someone local can test panel to rule it out, then maybe pay to have new wiring harness fitted as wiring very untidy and messy

 

If they are any good, they will want the panel on and connected to the boat. Otherwise, they will need to make up a jury-rig to test it, and you will pay for that.

 

I have told you how to carry out a simple test, I have even told you what you probably need to look for, and your comment about the wiring suggest that I am probably correct about how it is wired. I am not going to flog this particular dead horse because there is no point in repeating myself time and time again, I will leave you to rack up bills.

 

 

Edited October 5, 2023 by Tony Brooks

[Alan de Enfield]

[christophert]

22 minutes ago, Tony Brooks said:

 

But the rev counter does not have a sender as such so if that has stopped working it either means the alternator has failed or it is something else and all your symptoms indicate it is the lack of a negative to the gauges. No negative would affect all three instruments you listed.

 

 

If they are any good, they will want the panel on and connected to the boat. Otherwise, they will need to make up a jury-rig to test it, and you will pay for that.

 

I have told you how to carry out a simple test, I have even told you what you probably need to look for, and your comment about the wiring suggest that I am probably correct about how it is wired. I am not going to flog this particular dead horse because there is no point in repeating myself time and time again, I will leave you to rack up bills.

 

 

As I explained in an earlier post, this test was done by the engineer.  I have no intention of racking up bills but thank you for your advise.

6 minutes ago, Alan de Enfield said:

Why the insult? I came on here looking for advice and support, which has been given by some kind considerate people. I'm very knowledgeable in my own field of expertise, and can certainly think and work out complex problems which others may not be able. 

It's people like you who put off others seeking help with the likes of your visual comment. 

Behaviour like that is, in my opinion, quite sad.

[Alan de Enfield]

8 minutes ago, christophert said:

Behaviour like that is, in my opinion, quite sad.

 

You are entitled to your opinion, but I think the opinion of you by several very experienced forum members is that you are not listening to advice, not willing to even test things suggested and that you are seemingly no longer worth making the effort to help.

[christophert]

2 minutes ago, Alan de Enfield said:

 

You are entitled to your opinion, but I think the opinion of you by several very experienced forum members is that you are not listening to advice, not willing to even test things suggested and that you are seemingly no longer worth making the effort to help.

As you explained. The test has already been done! 🙄 It seems you're not listening, too busy insulting.  

Just now, christophert said:

As I explained. The test has already been done! 🙄 It seems you're not listening, too busy insulting.  

 

[David Mack]

5 minutes ago, christophert said:

As I explained in an earlier post, this test was done by the engineer.  I have no intention of racking up bills but thank you for your advise.

And Tony is suggesting you do the test yourself. 

You have no idea how many newbies pop up on here saying a 'professional' has looked at or tested some aspect of their boat and declared it unrepairable. Some of those newbies get all huffy when someone suggests their 'professional' may not actually be competent in the particular area under discussion, get angry when the advice from experienced boaters here conflicts with what they have been told, and some flounce out never to be heard of again. Others listen to what they are told on the forum, ask questions about points they don't understand, and are guided through a few DIY tests to narrow down exactly what the problem is or which component may have failed. And in many cases all it has taken is a simple DIY fix to solve the problem.

So if someone on here asks for further details of the problem, or perhaps some photos, or suggests a couple of simple tests, take this as well-intentioned (and free) advice that could save you hundreds of pounds.

[christophert]

7 minutes ago, David Mack said:

And Tony is suggesting you do the test yourself. 

You have no idea how many newbies pop up on here saying a 'professional' has looked at or tested some aspect of their boat and declared it unrepairable. Some of those newbies get all huffy when someone suggests their 'professional' may not actually be competent in the particular area under discussion, get angry when the advice from experienced boaters here conflicts with what they have been told, and some flounce out never to be heard of again. Others listen to what they are told on the forum, ask questions about points they don't understand, and are guided through a few DIY tests to narrow down exactly what the problem is or which component may have failed. And in many cases all it has taken is a simple DIY fix to solve the problem.

So if someone on here asks for further details of the problem, or perhaps some photos, or suggests a couple of simple tests, take this as well-intentioned (and free) advice that could save you hundreds of pounds.

I agree, and I'm very grateful for the advise I have received. I'll try all that has been suggested and Prime am very appreciative of the support I have been given. I just don't like being insulted.  I and I'm sure many others who come on here may struggle with getting their head around certain aspects of understanding the situation. 

I give out a lot of advice in my own field and sometimes teach. Sometimes people get it straight away and sometimes they don't, but I would never belittle or insult them. 

Everyone has been very helpful and supportive, apart from the donky poster, who in my opinion shouldn't be engaging if he cannot be constructive.

Thank you for your support, it is most appreciated.

 

[Tony Brooks]

2 minutes ago, christophert said:

I agree, and I'm very grateful for the advise I have received. I'll try all that has been suggested and Prime am very appreciative of the support I have been given. I just don't like being insulted.  I and I'm sure many others who come on here may struggle with getting their head around certain aspects of understanding the situation. 

I give out a lot of advice in my own field and sometimes teach. Sometimes people get it straight away and sometimes they don't, but I would never belittle or insult them. 

Everyone has been very helpful and supportive, apart from the donky poster, who in my opinion shouldn't be engaging if he cannot be constructive.

Thank you for your support, it is most appreciated.

 

 

From where I am standing, it seems to me that it is you who has not been engaging. You have provided no explanation of exactly what test was done to show an "earth" problem - even though I asked for it. You have given no indication, until now, that you intended to carry out the test, but what you have done is asked about the advisability of certain courses of action that are not supported by the symptoms, that you or your "engineer" think is needed. You

have not asked for any further explanation of why the gauges go to full scale deflection if they lose their negative connection.  If you had studied my website it would have explained why, or I would have happily told you if you had asked.

 

We don't know what you don't know or know, so without input from you, how do you expect us to help. Especially after receiving some posts suggesting your "engineer" may well be wrong/incompetent in electrical matters.

 

 

13 minutes ago, christophert said:

I give out a lot of advice in my own field and sometimes teach. Sometimes people get it straight away and sometimes they don't, but I would never belittle or insult them. 

 

As do I and I have also taught my subjects with professional qualifications (not that they really amount to much). In fact, I think we have members who have taken my courses in the past, so can perhaps give a personal assessment of my worth. Now, if you gave someone your best advice, and they gave every indication they were intent on ignoring it, while coming back for more advice, how would you react?  I think that I would be justified in directing an opinion about your conduct in your direction, but you will note that I did not.

 

Unfortunately, it is becoming more and more common for people to ask for advice and then ignore such advice if it does not accord with what they think is the case. Whether it is true or not, your posts seemed to be of that ilk, so no wonder people made comments pointing that out.

[Tracy D'arth]

Any "engineer" who turns up and cannot find the fault is not an engineer, in fact, no use at all.

[Tony Brooks]

See if this helps.

 

These are piggy-back connectors. The female blade pushes over the terminal on the instrument allowing a feed to the next instrument to be pushed onto he male blade.

 

Although this is a fuse panel, it shows the looped in system with two wires in one crimp terminal.

 

 

 

In both cases a bad connection will give the symptom you have, and with the looped in system it can be hard to spot.

 

There are also things called Scotchlocks that allow wires to be looped along the instruments. This is a Scotchlock.

These have a horrible habit of breaking the conductors in a wire so you get an open circuit. These are even more difficult to spot.

 

 

Why not post a photo of the back of the panel with wires attached.

 

[christophert]

1 hour ago, Tony Brooks said:

See if this helps.

 

These are piggy-back connectors. The female blade pushes over the terminal on the instrument allowing a feed to the next instrument to be pushed onto he male blade.

 

Although this is a fuse panel, it shows the looped in system with two wires in one crimp terminal.

 

 

 

In both cases a bad connection will give the symptom you have, and with the looped in system it can be hard to spot.

 

There are also things called Scotchlocks that allow wires to be looped along the instruments. This is a Scotchlock.

These have a horrible habit of breaking the conductors in a wire so you get an open circuit. These are even more difficult to spot.

 

 

Why not post a photo of the back of the panel with wires attached.

 

Thank you Tony, I will order these and replace the old ones. Tomorrow I'll do the test you recommend and take a pic of the back of the panel and post it here. 

[Tony Brooks]

47 minutes ago, christophert said:

Thank you Tony, I will order these and replace the old ones. Tomorrow I'll do the test you recommend and take a pic of the back of the panel and post it here. 

 

Please don't order anything. I posted those images to help you identify how your gauges are wired. Hopefully the photo(s) will help. There are other ways, including putting two eye terminals on one instrument stud.

 

If it is easier, you can link the voltmeter negative to each instrument negative in turn, turn the ignition on, and see if the gauges jump back to cold/no pressure.

 

If your instruments started waving about all over the place at random times, it speaks for a loose connection.

[christophert]

19 hours ago, Tony Brooks said:

See if this helps.

 

These are piggy-back connectors. The female blade pushes over the terminal on the instrument allowing a feed to the next instrument to be pushed onto he male blade.

 

Although this is a fuse panel, it shows the looped in system with two wires in one crimp terminal.

 

 

 

In both cases a bad connection will give the symptom you have, and with the looped in system it can be hard to spot.

 

There are also things called Scotchlocks that allow wires to be looped along the instruments. This is a Scotchlock.

These have a horrible habit of breaking the conductors in a wire so you get an open circuit. These are even more difficult to spot.

 

 

Why not post a photo of the back of the panel with wires attached.

 

Looking at picture, too left is volt meter which works, top right is ignition set up, bottom left is temperature, and bottom right is oil pressure. 

[Tracy D'arth]

There are a male and female connectors near the oil gauge that are not connected to each other, brown/yellow wire and brown wire.

[christophert]

Hi Tracy, I have traced the brown yellow to the alternator, I think it's redundant from an earlier alternator. There is no male connector on the back of alternator for it to connect to

The brown wire is a bit of a mystery. It may be to the horn button which is damaged and disconnected, though not sure that's where it went to.

[christophert]

20 hours ago, Tony Brooks said:

 

Please don't order anything. I posted those images to help you identify how your gauges are wired. Hopefully the photo(s) will help. There are other ways, including putting two eye terminals on one instrument stud.

 

If it is easier, you can link the voltmeter negative to each instrument negative in turn, turn the ignition on, and see if the gauges jump back to cold/no pressure.

 

If your instruments started waving about all over the place at random times, it speaks for a loose connection.

Hi Tony, I ran a wire from neg batteries terminal to oil then temp negatives. Clicks still behaved the same.

I'll now try running wire from volt meter neg to oil and temp neg 

[Tracy D'arth]

Is there the slightest possibility that both the wires from the clocks that go to the senders have been chaffed through so that they are shorted to the engine block or the hull?

That would give exactly the same result, full scale deflection of the gauges.

If you disconnect the sender wires at the clocks end, do the gauges drop back?

Edited October 6, 2023 by Tracy D'arth

[Tony Brooks]

1 hour ago, christophert said:

Hi Tony, I ran a wire from neg batteries terminal to oil then temp negatives. Clicks still behaved the same.

I'll now try running wire from volt meter neg to oil and temp neg 

 

Many thanks for that info. That lot looks a lot neater than man.

 

Now I can see the photo it seems that your gauges have illuminating lamps in them and I think they will be the ones with conventional pair of blade terminals. If you used the negative for these (probably black) then it would make absolutely no difference to the instruments.

 

The cables that work the instruments seem to be in three entry plugs. The white cables are probably 12V + when the ignition is one, the black 12V-, and the other colour (green, white with a brownish trace, and what looks like black with blue splodge on the rev counter) are the sender cables. So you need to connect to the black wires, a thin screwdriver down the hole in the black plastic shroud will usually or push a pin right through the cable.

 

I notice that it looks as if there is a black cable on the ignition switch and with this cable colour code black is definitely negative. There is no way a true negative cable should be connected anywhere on the ignition switch. This black wire needs tracing to see what the other end is connected to.

 

Try a voltmeter or test lamp between engine battery positive and the negative connection in the three-way shrouds on the gauge in turn. In each case the meter should read battery voltage (12V+) or the test lamp should illuminate. If it does not, then it confirms there is no negative connection.

 

FWIW I can't see any obviously bad connections.

PS, what are these "Clicks", would that be clocks?

 

11 minutes ago, Tracy D'arth said:

Is there the slightest possibility that both the wires from the clocks that go to the senders have been chaffed through so that they are shorted to the engine block or the hull?

That would give exactly the same result, full scale deflection of the gauges.

If you disconnect the sender wires at the clocks end, do the gauges drop back?

 

The OP said, but not in so many words, that the rev counter is not working and if that cable had shorted it would have shorted one phase of the alternator and possibly burned. This is why I still suspect no negative.  It will do no harm to do as you suggests but I am not sure how easy it is to pull the sender wire out of the black shroud and leave the others in place. If it is possible/easy, it would eliminate such a short or faulty senders.

PS, if you can confirm there is a working negative connection on the three instruments, then the fault is far more complex and your engineer deserves an apology from me.

 

As a lot of the black cables seem to be singles rather than twins in the connections and running back into the harness, I wonder if there is a negative connector block for the instruments elsewhere, or they have been joined within the loom.

Edited October 6, 2023 by Tony Brooks

[christophert]

5 hours ago, Tracy D'arth said:

Is there the slightest possibility that both the wires from the clocks that go to the senders have been chaffed through so that they are shorted to the engine block or the hull?

That would give exactly the same result, full scale deflection of the gauges.

If you disconnect the sender wires at the clocks end, do the gauges drop back?

Hi Tracy, as Tony said it may be difficult to separate the sender wires as all in one shroud, but over the weekend I'll see if it's possible as I'm wondering if it could possibly be the sender's. It's a 30 year old boat and may well be original senders. Although the chances of them failing together is doubtful, I wondered could some sort of power surge have knocked them out? Probably not but maybe possible I don't know. 

Although the rev counter is not working, this failed some time after and not the same time as the two gauges.

I'll also trace where that other wire leads to. 

The prospect of eating camel dung is more appealing than than trying to sort this out but it's gotta be done.

5 hours ago, Tony Brooks said:

 

Many thanks for that info. That lot looks a lot neater than man.

 

Now I can see the photo it seems that your gauges have illuminating lamps in them and I think they will be the ones with conventional pair of blade terminals. If you used the negative for these (probably black) then it would make absolutely no difference to the instruments.

 

The cables that work the instruments seem to be in three entry plugs. The white cables are probably 12V + when the ignition is one, the black 12V-, and the other colour (green, white with a brownish trace, and what looks like black with blue splodge on the rev counter) are the sender cables. So you need to connect to the black wires, a thin screwdriver down the hole in the black plastic shroud will usually or push a pin right through the cable.

 

I notice that it looks as if there is a black cable on the ignition switch and with this cable colour code black is definitely negative. There is no way a true negative cable should be connected anywhere on the ignition switch. This black wire needs tracing to see what the other end is connected to.

 

Try a voltmeter or test lamp between engine battery positive and the negative connection in the three-way shrouds on the gauge in turn. In each case the meter should read battery voltage (12V+) or the test lamp should illuminate. If it does not, then it confirms there is no negative connection.

 

FWIW I can't see any obviously bad connections.

PS, what are these "Clicks", would that be clocks?

 

 

The OP said, but not in so many words, that the rev counter is not working and if that cable had shorted it would have shorted one phase of the alternator and possibly burned. This is why I still suspect no negative.  It will do no harm to do as you suggests but I am not sure how easy it is to pull the sender wire out of the black shroud and leave the others in place. If it is possible/easy, it would eliminate such a short or faulty senders.

PS, if you can confirm there is a working negative connection on the three instruments, then the fault is far more complex and your engineer deserves an apology from me.

 

As a lot of the black cables seem to be singles rather than twins in the connections and running back into the harness, I wonder if there is a negative connector block for the instruments elsewhere, or they have been joined within the loom.

Hi Tony, clicks should've spelt clocks, I'll blame predictive texting. 

Over the weekend I'll try running negative wire from volt gauge and try volt meter between battery positive and negative in the three way shroud.

I'll also trace the black wire from the ignition switch to see where it leads to.

As I said to Tracy,  I was wondering if it could possibly be the sender's, thought very unlikely they failed at the same time, could a power surge have possibly knocked them out? 

She's a 30 year old boat and possibly the original senders in it, and the rev counter failed some time after the clocks stopped working, so poss separate issue. If so, I may have trouble getting replacement sender's to match the clocks as may now be obsolete.

But need to find out if there is a working negative, which hopefully these further tests will confirm either way.

 

 

[Tony Brooks]

9 hours ago, christophert said:

Hi Tracy, as Tony said it may be difficult to separate the sender wires as all in one shroud, but over the weekend I'll see if it's possible as I'm wondering if it could possibly be the sender's. It's a 30 year old boat and may well be original senders. Although the chances of them failing together is doubtful, I wondered could some sort of power surge have knocked them out? Probably not but maybe possible I don't know. 

Although the rev counter is not working, this failed some time after and not the same time as the two gauges.

I'll also trace where that other wire leads to. 

The prospect of eating camel dung is more appealing than than trying to sort this out but it's gotta be done.

Hi Tony, clicks should've spelt clocks, I'll blame predictive texting. 

Over the weekend I'll try running negative wire from volt gauge and try volt meter between battery positive and negative in the three way shroud.

I'll also trace the black wire from the ignition switch to see where it leads to.

As I said to Tracy,  I was wondering if it could possibly be the sender's, thought very unlikely they failed at the same time, could a power surge have possibly knocked them out? 

She's a 30 year old boat and possibly the original senders in it, and the rev counter failed some time after the clocks stopped working, so poss separate issue. If so, I may have trouble getting replacement sender's to match the clocks as may now be obsolete.

But need to find out if there is a working negative, which hopefully these further tests will confirm either way.

 

 

 

If you managed to connect the engine battery negative to the gauge negatives (not the illuminating lamp negatives) then there is no point in using the vltmeter negative. That is the same as the battery negative electrical wise.

 

It could be the senders, but as the vast majority of canal boat rev counters do not have a sender as such, it seems it is something common to all three instruments. The rev counter is almost always driven by pulses from the engine alternator. If the voltmeter reaches in excess of 14.2 volts after several hours running, and gets to 50 amps plus at first start up then the alternator is probably ok. This depends upon the alternator model and make.

 

So one must consider what is common to all three instruments. That is the positive and negative on the instruments. As the two gauges move to full scale defection that rules out the positives unless there is a separate fault on the rev counter. The full scale deflection is absolutely typical of no negative connection, so that is why a number of us have said that.

 

The fact that your gauge negatives are not looped from one gauge to the next suggest there is a terminal block somewhere with a load of negative wires connected to it. Have you found such a thing? The same may apply to the white positives.

 

There are other possibilities, but the negatives have to be proven as working before anything else. However, most boats have one or two multi-plugs in their main engine harness. Often low down close to the engine bed. These cause all sorts of odd problems when they become loose, dirty or corroded, so if your boat has one then it needs parting, wriggling etc. The negative "supply" probably runs through this block, but as the voltmeter is working and there is only likely to be a single cable then the voltmeter should have stopped working as well - UNLESS it is connected to the domestic bank of a twin alternator boat. Even then, the link between the engine and domestic battery negative terminals should have allowed the instruments to work. Testing with the cable between the engine battery negative and the instrument negatives should have ruled this out because the multiplug was not bypassed.

[Tracy D'arth]

The fact that the tacho packed up after the other gauges would suggest to me that it is wires frayed or damaged in the loom to the engine or damaged multi plug in the engine loom.

[Tony Brooks]

17 minutes ago, Tracy D'arth said:

The fact that the tacho packed up after the other gauges would suggest to me that it is wires frayed or damaged in the loom to the engine or damaged multi plug in the engine loom.

 

Where did the OP say that? All I could see is that he said they all do not work properly. If I missed it then you may well be correct.

 

 

[Tracy D'arth]

15 minutes ago, Tony Brooks said:

 

Where did the OP say that? All I could see is that he said they all do not work properly. If I missed it then you may well be correct.

 

 

  On 05/10/2023 at 12:11, Tonka said:

and does that fee include new senders which may be needed to match the new guages

I'm wondering if changing the sender's is first port of call. Chances of both going together is slim but worth a pop.The rev counter failed after the gauges behaved as though they were shorting, so possibly a separate issue

  On 05/10/2023 at 12:08, Tracy D'arth said:

There are mobile auto electricians in Tamworth, Coventry, Nuneaton and Atherstone according to Yell.

BUT if you buy a new pane

[Tony Brooks]

If it is the senders and not a short on the cable, simply pulling the wore off the sender should allow the gauges to drop back to rest. I am sure someone else suggested this. There is absolutely no point in changing components until they have been proven faulty. So far, we have no proven fault. The sender resistance can also be checked with a meter. The ASAP site used to have the resistance data.

 

INSTRUMENT SENDERS

 

Oil pressure US standard 240 Ohms @ 0 psi > 33 Ohms @ max pressure

Oil pressure European 10 Ohms @ 0 psi > 180 ohms @ max pressure

 

NOTE: The above only applies to modern senders – some older ones “pulse” the signal

 

 

Temperature US Standard 450 Ohms @ 100F > 30 Ohms @ 250F

Temperature European 280 Ohms @ 40C > 22 Ohms @ 120C