Club 80-90 Forums

Hi All, my battery light is staying on, intermittently, though a voltmeter tells me that the alternator current is fine and battery is being charged. Notably the light usually goes off as I go over a speed bump, so i'm pretty sure I have a bad earth somewhere.

Anyway, to help me diagnose it - whereabouts is the component that decides whether the current is correct - in the dash or somewhere else?

This diagram was posted by MidLifeCrisis in this post.



The blue wire from the alternator D+ terminal to the dashboard is the key here. I'd guess the problem is probably at the alternator end - check the condition of the terminal on the blue wire. If it's not at that end, then the other end is on the multipin plug that connects to the dashboard - might be worth wiggling that plug a bit. There's also a junction in that wire behind the fuse box (or there is in my '83 van anyway).

Thanks - very helpful

The only voltage sensing component is the bulb (More likely a bulb on your van) or diode and resistor, when the voltage is the same each side of the light no current flows through it therefore no light is on. If as said there is a dodgy connection either end it can affect the voltage so that there is a voltage difference hence the light shines.