Electrical/ charging problems

[Guest]

Some chandlers sell a relay that is rated at 100A and encased in a black case about 1.5 inches cubed. I have seen several melt, drop voltage or simply pass no voltage. I wonder if this is one such relay?

[Ricco1]

I've removed the cube thingy it's a Lucas 33ra, seems to be a relay. Connections seemed ok but I'm going to clean it up before I put it back on.

[Guest]

I've removed the cube thingy it's a Lucas 33ra, seems to be a relay. Connections seemed ok but I'm going to clean it up before I put it back on.

It might tide you over, but I would advise getting a more substantial relay for this job.

[blodger]

I've removed the cube thingy it's a Lucas 33ra, seems to be a relay. Connections seemed ok but I'm going to clean it up before I put it back on.

 

Well they are spec'd for 60a so should be good for 40a. Replacements are 12/15 squid IIRC. Personally I would pay a bit more and get a 100/140 amp one ready for when you upgrade the alternator. (I am sure you will have to in time )

[Guest]

After many charging problems, crap relays, diodes that dropped more voltage than promised, I spoke to this company and they fixed me up with some excellent relay type kit for a good price. http://www.intellitecmv.com/former/battery-guard-2000-100amp.htm

 

Needless to say the usual suspects on here at the time ridiculed the kit that I fitted, but nine years later all is charging well.

[Ricco1]

Progress! I cleaned up the contacts between the wires and the relay and refitted the relay. Whereas before the voltage at the relay was 1 volt less than at the alternator the difference is now only .1-.13. And the contact at the relay is no longer warm to the touch. So it seems that element of the problem might be solved.

 

But...my alternator is now showing only 13.85 volts with the engine running at a fair old speed. I've already identified that the belt running the alternator is loose and at the end of its adjustment. I need to buy a new one. Is this the most likely cause of the less than expected voltage here?

[blodger]

Progress! I cleaned up the contacts between the wires and the relay and refitted the relay. Whereas before the voltage at the relay was 1 volt less than at the alternator the difference is now only .1-.13. And the contact at the relay is no longer warm to the touch. So it seems that element of the problem might be solved.

 

But...my alternator is now showing only 13.85 volts with the engine running at a fair old speed. I've already identified that the belt running the alternator is loose and at the end of its adjustment. I need to buy a new one. Is this the most likely cause of the less than expected voltage here?

 

 

 

 

There you are easy peasy

 

The batts now they are better connected will drag down the alternator voltage but they should slowly rise to the alternator regulated voltage which you want to be at least 14.2/14.4v,

 

Eve 40 amps is a fair old load on a belt so it is bound to slip; they do not always squeal their plight. So it is bound to be having a detrimental effect; its being slack that is.

Edited October 12, 2013 by blodger

[ditchcrawler]

I've removed the cube thingy it's a Lucas 33ra, seems to be a relay. Connections seemed ok but I'm going to clean it up before I put it back on.

Well done, your on the track

[by'eck]

Progress! I cleaned up the contacts between the wires and the relay and refitted the relay. Whereas before the voltage at the relay was 1 volt less than at the alternator the difference is now only .1-.13. And the contact at the relay is no longer warm to the touch. So it seems that element of the problem might be solved.

 

But...my alternator is now showing only 13.85 volts with the engine running at a fair old speed. I've already identified that the belt running the alternator is loose and at the end of its adjustment. I need to buy a new one. Is this the most likely cause of the less than expected voltage here?

 

That charge voltage wouldn't be surprising if the alternator was re-charging drained/partially drained batteries. Check regularly to see that its slowly increasing up to at least 14.2 volts. A new tensioned belt will ensure there is no slip though.

 

Still might be worth replacing that relay - see here

Edited October 12, 2013 by by'eck

[nicknorman]

Yes, the fact that the alternator voltage has decreased is a good sign - it means that the alternator is supplying much more current. But as has been said, keep charging until the voltage doesn't increase any more, and then another couple of hours to at last get vaguely close to fully charged.

[Ricco1]

I've now got a new v belt, I'm trying to fit it.

 

The alternator is at maximum on the adjustment bracket. I need to swing it back in order to take the old one off and put the new one on. I've loosened the bolt at the adjustment bracket but the alternator won't budge. The manual: "loosen the bolt of the adjustment bracket and both the alternator mounting bolts". The only other bolts I can see in the area are 2 Phillips head ones, these appear to hold the alternator together rather than mount it. Of course it's very difficult to see everything because the alternator is at the back of the engine, little room to work in.

 

Is it usual to have to loosen more than the bolt of the adjustment bracket in order to move the alternator? If so, where might I look more closely for the other bolts?

 

Also, a hose that runs to the bottom of the skin tank goes through the area that the belt encompasses. So, I'll need to do something about that in order to fit the new belt. It seems I might be able to undo a hose clip and pull the hose out of the way. Can you see any problems doing that?

 

Thanks

[nicknorman]

The alternator will be mounted in up to 3 places

 

1/ the slotted adjustment arm

 

2/ a bolt at the point where the alternator is mounted / pivots on the engine at the front

 

3/ a bolt at the point where the alternator is mounted / pivots on the engine at the back

 

Sometimes 2 and 3 are just one long bolt.

 

You need to loosen all three (or two) of these bolts.

 

If you need to remove the hose, you may lose coolant and or suffer from an airlock afterwards. It depends on how high the hose is compared to the engine and skin tank.

 

Firstly, obviously, do it when the engine is cold or only warm. I would try to minimise coolant loss by clamping the hose eg with mole grips and / or have something to hand to block the exposed ends, and a means to collect any spillage and put it back in the engine. Don't forget that anti-freeze is poisonous to marine life.

 

If there is a header tank it might be worth emptying this first so as to reduce the amount of fluid lost.

Edited October 13, 2013 by nicknorman

[Ricco1]

The manual appears to be wrong. I've found a schematic on the internet which shows the same arrangement as mine appears to be. There is a long bolt which covers 2 and 3 as described above. Unfortunately the accessible end of the bolt is a dome head. The other end, a nut, is shrouded by a hose and what I think is the exhaust manifold. I really do wonder about the person who designed this, why have the only accessible part of the bolt a dome head, which no tool can grip, in order to carry out a routine task??

 

It appears that I'm stuck, as no way do I feel confident enough to start dismantling the engine.

[nicknorman]

Perhaps you should get a mate to have a look at it? Sometimes a fresh pair of eyes is needed. Surely it can't be that difficult to adjust the alternator belt tension! Does the domed bit you refer to not have a hex head further in, which could be "got to" with socket?

[Ricco1]

Yes I think it's time to take a break until someone else has a look. Because of where the bolt is I can only see it using a mirror. With a torch as well, it's very clear that the head is domed. Behind this is the engine casing, then a spacer, engine casing again followed by the shrouded nut. Maybe the bolt has been installed the wrong way round. One thing is for certain, when I manage to undo it the nut will be at the accessible end for next time!

[nicknorman]

It seems odd to have a domed end with no means of stopping it from turning. Maybe it has a square section that fits into a square recess, in which case it might not fit the other way round. I wonder if its a coach bolt that has been fitted as a bodge after the original bolt sheared?

[smileypete]

Maybe just try levering the alt outward with the handle of a large hammer, or a bit 'o wood.

 

cheers, Pete.

~smpt~

[Ricco1]

Maybe just try levering the alt outward with the handle of a large hammer, or a bit 'o wood.

 

cheers, Pete.

~smpt~

 

I'm going to try that tomorrow. Can I use a fair amount of force? Is there a possibility of damaging the alternator doing this?

[smileypete]

I doubt it would get damaged by levering it with a hammer handle or something that long, or tapping it in with a mallet. I'd also put a goodly amount of penetrating oil or WD40 around the pivot bolts and the metal in between first and allow it to soak in, and work it both ways at first.

 

cheers, Pete.

~smpt~

Edited October 13, 2013 by smileypete

[Tony Brooks]

 

Well they are spec'd for 60a so should be good for 40a. Replacements are 12/15 squid IIRC. Personally I would pay a bit more and get a 100/140 amp one ready for when you upgrade the alternator. (I am sure you will have to in time )

 

That is only if the main charging cable is wired to the domestic bank and the relay connects the engine battery. Many are not wired like this because nit involves more work.

 

If the main charging wire runs to the engine battery with certain methods of relay excitation and under certain conditions a significant proportion of the starting current can flow through the relay so My advice, whatever relay is fitted, is to trace the wiring and make sure the alternator output goes to the domestic bank and the relay connects the domestic bank to the engine battery.

[Ricco1]

An update on this:

 

I managed to move the alternator by hitting it with a hammer, protected by a piece of wood. Next I removed the hose that goes to the bottom of the skin tank. As soon as I got it off I tied the hose to something above with fishing line. Maybe lost half a pint or so of water, hopefully that won't cause a problem with an air lock.

 

I then fitted the new v belt. I think I have the right one, 905mm as stated in the manual, but I had to tap the alternator almost to the maximum adjustment position in order to get the belt tight. Disappointing this, means I'll have to do the job again when the belt stretches.

 

It was a pig to get the hose on again without leaking. Mostly because there's not much room to work, or even see anything down there. Anyway I think I nailed it (not literally!), but I'll check it again a few times over the next day or two, just to make sure.

 

I filled the water header tank, was surprised that none went into the engine, which had emptied of water when I removed the back hose. Is this normal? Anyway, I filled up via the filler cap on top of the engine.

 

I ran the engine, was getting 14.25 volts at the alternator on lowish revs, 14.15 at the relay.

 

So unless I've made a hideous mistake when refilling with water, created an air lock somewhere, and subject to double checking for leaks I think I'm now in the position to assess whether my batteries are goosed or not!

[smileypete]

Well done! Maybe get a very slightly shorter belt as a spare.

 

cheers, Pete.

~smpt~

[nicknorman]

Well done. Its normal for the coolant to be difficult to get back into the system from the header tank, but often just removing the cap on the engine to let the air out, is sufficient to get the coolant in from the header tank. If there is some air in there, with thermal cycling (ie engine heating up, then cooling down again a couple of times) chances are the air will be expelled and replaced by coolant, so keep an eye on the header tank for the first few runs of the engine.

 

Note that I am saying "coolant" here, not "water" since its important to have anti-freeze in the system. Not just in case of freezing, but also importantly because the anti-freeze contains a corrosion inhibitor. If you operate just on water, you will run into problems with the insides of the engine disappearing over only a moderate timescale.

 

ETA its possible that at some point the alternator has been replaced or refitted with a smaller pulley. This has the advantage of making the alternator run faster for a given engine speed, but obviously slightly reduces the belt length required. As SP says, try a slightly shorter belt next time.

Edited October 14, 2013 by nicknorman

[bizzard]

There's often a lot of meat left at the maximum end of the elongated slot in the adjusting bracket, if so the slot could be lengthened a bit further with a round file which would give a bit more belt tightening adjustment, You might be able to file it in situ if there's enough room.

[Ricco1]

Well done. Its normal for the coolant to be difficult to get back into the system from the header tank, but often just removing the cap on the engine to let the air out, is sufficient to get the coolant in from the header tank. If there is some air in there, with thermal cycling (ie engine heating up, then cooling down again a couple of times) chances are the air will be expelled and replaced by coolant, so keep an eye on the header tank for the first few runs of the engine.

 

Note that I am saying "coolant" here, not "water" since its important to have anti-freeze in the system. Not just in case of freezing, but also importantly because the anti-freeze contains a corrosion inhibitor. If you operate just on water, you will run into problems with the insides of the engine disappearing over only a moderate timescale.

 

ETA its possible that at some point the alternator has been replaced or refitted with a smaller pulley. This has the advantage of making the alternator run faster for a given engine speed, but obviously slightly reduces the belt length required. As SP says, try a slightly shorter belt next time.

 

Thanks Nick. Anti-freeze is the next on my must-do list. I've now worked out how much I need but have yet to work out how to do it. I can easily empty the header tank and engine. As for the skin tank, which I will have to partially empty, I don't know yet. I'm waiting for a bit of money to come in, no doubt I'll start a new thread in due course!

There's often a lot of meat left at the maximum end of the elongated slot in the adjusting bracket, if so the slot could be lengthened a bit further with a round file which would give a bit more belt tightening adjustment, You might be able to file it in situ if there's enough room.

 

That is an excellent idea. I guess the end of the slot doesn't really support anything, could be filed until there's very little of it left. I'll do this!