I’ve got a bit of a strange one here. I lent my ’84 240GL to my brother (my first mistake!). He brought it back, saying that all the warning lights where intermittently glowing. Took it for a drive, and the sure enough, all the lights were on, at about half brightness, as compared to when the ignition is on, but the engine is not running. Pull on the hand brake, and they brighten a bit, but not to full brightness.

Figuring that it may be an earth fault with the alternator, I installed a new earth, and the problem disappeared. Took the car out again, and at 4,500RPM, the lights glowed again, but went off when the revs dropped. Later they came on at 4,000 RPM, then 3,5000 etc. Now they are on all the time again. There is a good earth to the alternator, and I have no idea where to start looking for a fault. The alternator is less than 6 months old. The engine wiring harness has been replaced (home made job). Also when I pull the alternator warning sending wire out of the alternator and earth it, only the Alternator warning light comes on. Could really use some help here!

Thanks in advance
Matt Jones