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MG Midget and Sprite Technical - Ignition Light.

The ignition light glows dimly all the time the engine is running regardless of what revs.
The alternator is new, the belt is tight and there seems to be no problem with charging but the light never completely goes out.

Any ideas?
Roger D

Possibly regulator or cut-out not working properly?
Tim Carter

I had the exact same problem with a Newly refurbished alternator I bought at Stoneleigh from a company.

They immediately replaced it and said it was a fault in the diode pack.
New one fitted OK since (now jinxed !)

Richard.
richard b

I don't think it's an alternator problem as the problem was there before I replaced the alternator. With hindsight maybe the alternator didn't actually need replacing.
As it is not producing any problems, can I ignore it?
Roger D

Maybe you had two faulty alternators.
Dave O'Neill 2

Roger. The ignition warning light shows an imbalance between the battery side of the circuit and the alternator side of the circuit. The brighter the light glows, the greater the imbalance. That is why the light glows brightly prior to start up when all of the electricity is coming from the battery.

Have you put a volt meter on various points in the system? Battery terminals, battery clamps, and voltage from somewhere in the engine compartment with the engine running? You may wish to do those checks and post what you find.

Les
Les Bengtson

Agree with Les. It sounds like a poor (high resistance) wire termination to me. Even a dirty contact in the lamp holder itself could lead to enough voltage drop on one side to cause the imbalance he mentioned.
Greybeard

I agree with Les and Grey. There may be resistance in the ignition switch contacts. This would cause a volt drop such that the ignition light has a small voltage across it, enough to make it glow.
Bill B

This thread was discussed between 12/12/2024 and 13/12/2024

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