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MG Midget and Sprite Technical - Ignition light on

OK, had a Homer moment this morning, in my defense, it was 3.30 am, working out in a snow blizzard and I was late for work!

I connected the battery the wrong way round!

After I swapped the connections over, the car started and I went to work (and returned home), using headlights, wipers and heater. It's an hours drive each way and the battery hasn't gone flat, so the alternator seems to be charging!

The igntion light goes out when the ignation is switched on and while the engine is running, but the car is switched off, the light comes on.

What bit I have I broken and please don't worry, although it's 1960's Lucas, no Spidgets were harmed during this incident!

AndyB
Andy Borris

Probably the regulator , that is an integral part of the alternator . Just think yourself lucky you dont have electronic ignition as you would have fried that as well .. Roy
R Mcknight

Do have electronic ignition!

Must be a very robust one.....

AndyB
Andy Borris

Hi Andy slight problem is that in the regulator mounted at the rear of the Alternator there is a chip that switches off the connection from the alternator to the car, which in your case is now useless. Thus whilst the ignition light is on the battery will be discharging slightly. By how much could be as little as a couple of milliamps but likely to be a lot more.

If you disconnect the battery overnight this will keep you going until you ban either repair the alternator or buy a new one.
Robert (Bob) Midget Turbo

So if I fit one of these http://cgi.ebay.co.uk/NEW-12V-ALTERNATOR-LUCAS-15-16-17-18-ACR-REGULATOR-1084_W0QQitemZ300359141822QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item45eeccc9be,it'll work again?

AndyB
Andy Borris

If it fits your alternator yes!
Robert (Bob) Midget Turbo

Thanks Bob,

I'll get the hammer out and open it up for a looksee.

AndyB
Andy Borris

The girlfiend (looking over my shoulder as I type) said "hammer?", so for her benefit: A small hammer, I always use the correct tool for the job as a proper craftsman should.

Andy
Andy Borris

'Gary from London' and 'Mothy' are both listed as previous purchasers from that ebay seller - I wonder....
Doug Plumb

A very tiny hammer should do it Andy

:)

If you can find a part number on the alternator (or maybe show a picture of the offensive item) I may be able to find you a part number for a replacement regulator

I still have a "Alternators and Regulators - Part Number reference book" from my wicked past..

The item shown on the auction may not fit but if the seller on ebay is the company I think it may be they used to be very helpful.

and they offer a service so you can phone em for parts advice, too

might be worth a punt, their "buy it now" doesn't seem far off the mark TBH

let us have the number

(early Lucas alternators had different diode and regulator setups from the one in the advert, separate individual diodes in a frame work. Easier to see but harder to repair) LRA 100 and LRA 101 are that type usually
bill sdgpm

This thread was discussed on 07/01/2010

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.