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Lucas Relay SRB501 12V 28RA 20/30 Amp 5 Pin


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34 minutes ago, Puff Along said:

Hi A Newbie here....1.5 BMC Diesel .I renewed a Lucas Relay SRB501 12V 28RA 20/30 Amp 5 Pin ,I did a diagram of the what connector went where.But have lost it.Can some one PLEASE tell me what goes where....Thanks in  Nigel

 

Is that it, strapped to the green Morse cable? Why not just follow the wires and do another diagram? 

 

Boats are not like cars, well documented and all the same. No-one here knows how your boat was wired up. One or to might take an educated guess but there are no guarantees of accuracy.

 

Nice pike! 

 

 

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Cheers for that. A Edumacated Geuss me.I wouldn't bet on it.Always screw up stuff like this.

I will get a engineer to check it out.I don't want to do damage/

PIKE no [mind you they are a favourite of mine]That is a 25lb Steelhead Trout, a Rainbow that runs to the sea as our wild browns do and are called Sea Trout caught is on a Indian reservation in Washington state last year.Fish of 2 lifetimes. 

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2 minutes ago, Puff Along said:

PIKE no [mind you they are a favourite of mine]That is a 25lb Steelhead Trout, a Rainbow that runs to the sea as our wild browns do and are called Sea Trout caught is on a Indian reservation in Washington state last year.Fish of 2 lifetimes. 

 

'Kin'ell, a TROUT??? 25lb!!!!

 

You sure it wasn't Chernobyl you caught it? ?

 

 

 

 

Around here the trout in the fishmongers are about a pound...!

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Such sophistication!

 

I've never seen anything as technically advanced as a relay on a BMC 1500/1800 in a narrow boat.  Do you know what it is doing

 

Are you absolutely sure that is a BMC 1500?  I can't put my finger on what doesn't quite feel right about it, but something doesn't, (to me, at least).

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55 minutes ago, alan_fincher said:

I can't put my finger on what doesn't quite feel right about it, but something doesn't, (to me, at least).

 

The rocker box looks a funny shape to my eye....

 

I think its a sea boat too. Wet exhaust anyway, and doesn't look like a narrow boat hull.

 

 

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Its a 2.2 or 2.5. probably a 2.5 because it has 12V heater plugs.

 

The relay that seems to be fitted to the Morse cable seems to be energising the starter solenoid but it also seems to have the glow plug wire attached to it. It looks too small to be anything special so if I am correct that is very non-standard. You need to energise the glow plugs before spinning the starter.

 

Without history I think it may be past bodge to get over undersized wires. I would be inclined to rewire for two separate relays each doing one job.

 

Hold hard - I have just blow the image up a little and am wrong. Its just a glow plug relay that is fed from the main starter battery terminal. It does not need a five pin relay or one with a diode in it. A simple four pin one will do but preferably rated at over 40 amps. I would use an old car type remote starter solenoid.

 

The relay should have an image like this on it but it will have terminal numbers:

 

image.png.f479395bf600d192bd5d8eb031aa8205.png

 

The thick red wire from the stater solenoid goes to terminal 30

The brownish cable that gets painted green near the glow pugs goes to terminal 87

(May be reversed if easier)

 

The black wire coming from the flywheel housing goes to terminal 86

The other wire that I can't see but it comes from the ignition switch/glow plug button goes on 85

(may be reversed if easier)

 

 

 

 

 

 

 

Edited by Tony Brooks
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I'm always surprised just how many people think they know which BMC diesel they have, but actually have something else entirely.

I can only conclude they have not yet reached the stage of needing to buy many parts for them, or they would probably have found out it's not what they think it is!

Good detective work by Tony as usual. ?

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10 hours ago, Tony Brooks said:

Its a 2.2 or 2.5. probably a 2.5 because it has 12V heater plugs.

 

The relay that seems to be fitted to the Morse cable seems to be energising the starter solenoid but it also seems to have the glow plug wire attached to it. It looks too small to be anything special so if I am correct that is very non-standard. You need to energise the glow plugs before spinning the starter.

 

Without history I think it may be past bodge to get over undersized wires. I would be inclined to rewire for two separate relays each doing one job.

 

Hold hard - I have just blow the image up a little and am wrong. Its just a glow plug relay that is fed from the main starter battery terminal. It does not need a five pin relay or one with a diode in it. A simple four pin one will do but preferably rated at over 40 amps. I would use an old car type remote starter solenoid.

 

The relay should have an image like this on it but it will have terminal numbers:

 

image.png.f479395bf600d192bd5d8eb031aa8205.png

 

The thick red wire from the stater solenoid goes to terminal 30

The brownish cable that gets painted green near the glow pugs goes to terminal 87

(May be reversed if easier)

 

The black wire coming from the flywheel housing goes to terminal 86

The other wire that I can't see but it comes from the ignition switch/glow plug button goes on 85

(may be reversed if easier)

 

That's brilliant.Thanks Tony.It is a Sea Boat but thought as it is general Canal boat engine one of you would be able to put me straight.It came fitted like it .There is another one in marina with a slightly bigger BMC in it that hasn't got a relay.It's weird it has this fitted but No Fuel Shutoff Valve and a fuel pump with out a Lift mechanism.Both I have now purchase and waiting to fit .On reading different threads I think I also need another shutoff valve for the feed back pipe? Re the wiring i can now  [hopefully put the wire back as intended] Thanks again

 

 

 

 

 

 

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11 hours ago, Tony Brooks said:

Its a 2.2 or 2.5. probably a 2.5 because it has 12V heater plugs.

 

The relay that seems to be fitted to the Morse cable seems to be energising the starter solenoid but it also seems to have the glow plug wire attached to it. It looks too small to be anything special so if I am correct that is very non-standard. You need to energise the glow plugs before spinning the starter.

 

Without history I think it may be past bodge to get over undersized wires. I would be inclined to rewire for two separate relays each doing one job.

 

Hold hard - I have just blow the image up a little and am wrong. Its just a glow plug relay that is fed from the main starter battery terminal. It does not need a five pin relay or one with a diode in it. A simple four pin one will do but preferably rated at over 40 amps. I would use an old car type remote starter solenoid.

 

The relay should have an image like this on it but it will have terminal numbers:

 

image.png.f479395bf600d192bd5d8eb031aa8205.png

 

The thick red wire from the stater solenoid goes to terminal 30

The brownish cable that gets painted green near the glow pugs goes to terminal 87

(May be reversed if easier)

 

The black wire coming from the flywheel housing goes to terminal 86

The other wire that I can't see but it comes from the ignition switch/glow plug button goes on 85

(may be reversed if easier)

 Quite correct Sea Boat but as BMC seemed to be the old got too for canal use .Thought i would ask. Tony Brooks has put me right.Cheers

 

 

 

 

 

 

 

 

19 hours ago, Mike the Boilerman said:

 

The rocker box looks a funny shape to my eye....

 

I think its a sea boat too. Wet exhaust anyway, and doesn't look like a narrow boat hull.

 

 

 

9 hours ago, alan_fincher said:

I'm always surprised just how many people think they know which BMC diesel they have, but actually have something else entirely.

I can only conclude they have not yet reached the stage of needing to buy many parts for them, or they would probably have found out it's not what they think it is!

Good detective work by Tony as usual. ?

Only going on what was told to me when purchased.we all can't be as knowledgeable as you are.But thanks anyway!

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2 hours ago, Puff Along said:

That's brilliant.Thanks Tony.It is a Sea Boat but thought as it is general Canal boat engine one of you would be able to put me straight.It came fitted like it .There is another one in marina with a slightly bigger BMC in it that hasn't got a relay.It's weird it has this fitted but No Fuel Shutoff Valve and a fuel pump with out a Lift mechanism.Both I have now purchase and waiting to fit .On reading different threads I think I also need another shutoff valve for the feed back pipe? Re the wiring i can now  [hopefully put the wire back as intended] Thanks again

 

If its a sea boat the only thing that you need to worry about re fuel valves and a good deal else you will read about on here is what your insurance company say. As far as  am aware there is not Boat Safety Certificate or inspections for a  sea boat. If your return goes into the top of the tank and has no dip tube on the end I don't see you need another shut off valve.

 

The larger BMC engines (3.4  & 3.8) look similar but are direct injected so they do not use glow plugs and so they do not need a glow plug relay.

 

As canal use typically requires a few HP, even for a 70ft boat, The 2.2/2.5 is a touch on the large side although they are used occasionally, probably more often in wide beam boats rather than narrow boats.

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1 hour ago, Tony Brooks said:

 

If its a sea boat the only thing that you need to worry about re fuel valves and a good deal else you will read about on here is what your insurance company say. As far as  am aware there is not Boat Safety Certificate or inspections for a  sea boat. If your return goes into the top of the tank and has no dip tube on the end I don't see you need another shut off valve.

 

The larger BMC engines (3.4  & 3.8) look similar but are direct injected so they do not use glow plugs and so they do not need a glow plug relay.

 

As canal use typically requires a few HP, even for a 70ft boat, The 2.2/2.5 is a touch on the large side although they are used occasionally, probably more often in wide beam boats rather than narrow boats.

Tony Thank you again for your time/help....The engine size is complexing the previous owner purchased it in situ and was told it was a 1.8 BMC 80hp.He was then advised by a mechanic it was a BMC 1.5 40 OR 50HP So i don't know,except it is a 23' Duver made by Island Plastics that operated in the I/O/White She does 9/10 knots weighing 1.9 tons with fuel. 

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BMC 1.5s are rated at about 35 HP, The 1.8 probably about 42HP. From distant memory the 2.2 about 52 HP and the 2.5 is probably about 60HP  but as it had not been built when I was working on the hire fleet I don't know for sure.

 

The 2.2 had 2 volt glow plugs all connected in series with a resistor thing in a tin shroud but your glow plugs are smaller in the visible body and connected in parallel so are 12V and the 2.5 had 12V glow plugs as standard , however 12V plugs are available fro a 2.2  as after market fitments so the glow plugs are not a definitive identification. I can't see the injector pump so that is no help but if it is an inline one then it is almost certainly an early 2.2, The oil filter also suggests an early engine. It is notr a 1.5 because their injector pumps stuck out teh side of the block and would be easily visible in the photo.

 

The definitive way of identifying it is to find the engine number and post it here or to look on the side of the block under the manifold and hope BMC cast the capacity on the side.

 

PS, I would find another mechanic. I know BMCs are probably not that common in sea boats but to suggest that a 23 ft boat that will reach 9 knots has a 35hp engine is not very bright, even if he could not identify the engine exactly. That speed suggest that you can get it up on the plane otherwise the maximum displacement speed would be around 6 knots assuming a water line length of 22ft and a typical hull constant of 1.3.

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11 minutes ago, Spanners said:

Yes I,v worked on them

Looking at the engine mounts I don't think that is an official BMC/Newage/Tempest marinisation. But as the official ones used those idiot "top hat" Metalstic rear mounts that are unobtainable this one could have been modified to accept more conventional rubber mounts. It also looks more like BMC vehicle green than the darker marine green to me.

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8 hours ago, Puff Along said:

It seems it is a 2.5 for definite. I ordered a lift version for a 1.5  and the mounting are different the 1.5 mounting holes are Horizontal the 2.5 holes are offset high an low.So recorded a 2.5 lift pump 

 

 

From memory so are the 2.2s. Both engines (2.2 & 2.5)  are very similar with only minor obvious differences.

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3 hours ago, Tony Brooks said:

 

From memory so are the 2.2s. Both engines (2.2 & 2.5)  are very similar with only minor obvious differences.

The boat moored directly in front of me is owned by a diesel engineer.He served his apprenticeship on BMC Engines.So he is now taking on my problems.[thank goodness] Thanks for everyone's help.

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