This is for my MGB GT - I'm posting here as I know there are a number of electrickery experts whose opinions I value.
When driving my alternator light is very very faint, but still on. If I put on the windscreen wipers or washers it starts to glow more. However the alternator is still putting power into the battery - I have a plug in voltmeter and it's putting in around 13.8 - 14.4V. The voltage reading doesn't change when the wipers and washers are on.
I replaced the alternator last year and there has been no change.
In the last few days the alternator light has come on for a period of time - again, no effect on the charging, and still putting in 13.8 - 14.4V. Sometimes it turns itself off, other times, switching the ignition on and off cures the problem.
Any thoughts at where I should be looking? I'm assuming the problem would be with the lead from the light to the alternator? Broken or poor connection? But not sure why the light comes on with the wiper!
The car fuse box has been (badly) replaced and rewired at some point, and is in my fix list so may be a problem there?
Last edited by TBM; 05/02/25 09:52 AM.