Ignition warning light relay

Anyone know the part number and source of the electronic type replacement for the daft 3AW flasher unit lookalike relay for the warning light on '71 2000? Got plenty of charge just the light doesn't go out so assume this is the problem from reading other posts? Previous owner had just removed the bulb. Not really that bothered about the light, just nice to know if you have lost the fan belt! Cheers, Rob
Cheers for that. Was thinking of the option of replacing with ACR type alternator but with so many relays and control boxes would be a PITA, so think I will probably stick with the current system and get one of these relays till the 11AC gives up. Looks pretty new though, as if someone has replaced thinking that was the fault, so may last a while. As we've just got the car a week ago ish, we are still ironing out the niggles.
Think so, the wires look long enough on the new gizmatroid and loads of room up around the flasher units to sit the new relay. Let you know if it does. Going to have a good look round the autojumble guys at the Ripon show for an original one first.
Good day Gents. Picked up this thread.

My ignition light came on whilst driving and I do appear to have a problem with discharging(amp gauge showing discharge) and battery not holding a charge etc. I will look into this however the ignition light is not working at all now.

Can anyone provide some info how to get access to the light and possibly give me details for the light itself so that I can buy ?

Its a 1975 - 3500S.



Well-Known Member
A 1975 car should have an ACR alternator, so switch the ignition on, and then earth the smallest wire in the multiplug that fits into the back of the alternator. If the light comes on then it's a fault with the alternator, if not it's a fault with the supply to that point, which includes the ignition warning light bulb. The ACR won't charge if the light is on, or it has no supply through it. You will need to remove the perspex cover in front of the instruments to access the bulb. The bulb type will be listed in the WM. It's capless, but I can't remember the wattage.


Well-Known Member
No, the perspex has to come off. Prise off the two knobs on the LHS endplate, (Trip reset and panel lights dimmer), unscrew the two serrated flat retainers and remove the endplate, at the other end by the door pillar, pull out the small finisher using the little knob on it, then you will see 4 large Phillips screws, undo and remove those to remove the perspex.
Good day Gents.
Possibly someone can ID my Alternator ? Mark at MGBD parts doesn't seem to think its a Lucas GEU 228 unit and there is absolutely no markings on it.
I suppose my question is, if I do buy the GEU 228 unit, will it fit . Its a 1975 3500S but my late brother did a lot of work to it when he rebuilt the car back in 1996.
any advise or info would be appreciated .
Harvey, thanks for the previous info and all done as you suggested so, Alternator is the problem.


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Many thanks Colin.
Could I further trouble you to see if you think its a RH or a LH mounting ?
Is this terminology used when looking at the front of the car and with mine its LH mounted ?


Active Member
The LH & RH refers how the alternator is hinged and not where its located on the engine . I think yours is a LH. A lot of replacements even from Lucas in its day, could be mounted either way by taking out the long bolts between the two end casing, rotating the one relative to the other to change its hand . Originally one lug would be tapped to take the adjuster bolt, but by replacing with a bolt they become universal. The one you have looks to me that can be rotated to fit either LH or RH
Good morning Gents.
Sorry, have to touch base and ask more!
I took the unit off the car yesterday evening and I cannot find any markings on this whatsoever.
Please see the later attachment.
Before I go down the line to buy the new unit, I would appreciate if someone (possibly Colin) could confirm that it is indeed a Lucas A127 alternator.
I suppose my next question would be, if I cannot get the A127 very easy, will the GEU 228 unit fit ?
Thanks to all for your good help.


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Well-Known Member
Hi, Both types are interchangeable and fit a variety of vehicles, not just Rovers, you should have no trouble getting either or parts. Broadly speaking alternator mounts are fairly common across most makes.

Thanks Colin.
Will go for the LUCAS A127 since I see them on e bay at a touch over £50, this compared to MGBP at about £90
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