I have been scouring the forums trying to diagnose the electrical woes of my 86 951 for a while now, but I haven’t found anything quite like this. Let me run my symptoms by you folks and see if any of you have the cure.
If I start with a fully charged battery (less than year old) all the warning lights work properly. The ! and alt light light up when the key is first turned on, voltmeter a hair over 12. Start the car, the alt light goes out and release the brake, then the ! light goes out. Voltage is then almost to 14, and it was around 13 while running before the problems started. Driving down the road the voltage varies more than usual, but stays between 12 and 14. Get down the road about 5 minutes and the voltage drops to 12, and then gradually decreases from there. As if the regulator quit after it got warmed up. And I can not get it charge again after that, until the car cools off good.
Trying to fix this I just replaced the battery cables, the starter to alternator cable, and added an extra ground from the battery to the engine.
I’m thinking either regulator or alternator, leaning towards (wishfully) regulator. I replaced the regulator about a year ago (same time as the battery, surprise, surprise), but I have had to jumpstart and charge the battery a few times recently for unrelated problems. I thought that I had pulled the ground off of the battery every time I charged it, and charged it as soon as I got it home after a jump start, but I probably screwed up and toasted either the alternator or regulator. I know that I should just pull the alternator and have them checked as a unit, but this is a turbo and pulling that little beastie is no easy task. I replaced the regulator last year from under the car without pulling the alternator, and am hoping this is all I need to do again.
Maybe I should just get in touch with Iceshark and get one of his regulators to see if that solves my problem?
