Hello gents, After a couple of searches, I can't seem to find another issue quite like this, so here goes. When driving back from Monterey a couple of weeks ago, I noticed that my headlights were repeatedly sort of flickering dim and then bright in a morse-code like fashion - not on and off completely, just flickering brightness. I also had noticed that day that my radiator fan would kick in, and then kick out a few seconds later, then kick in again a few more seconds later sometimes. In addition, while I was sitting in traffic the fan turned on sounding normal and then a few seconds later the fan revs soared for a few seconds, then went back down to normal speed. The interior lights are also doing the bright/dim flicker action as well. The car is otherwise running great (had a major this past winter), lots of power, feels totally normal. Ideas? Cheers and thanks.
Might be the alternator/voltage regulator going haywire. Try measuring the battery voltage when the "bright" occurs -- if the (alternator output) voltage spikes up to a crazy value (like more than 15V), that would be a bad sign (and, if it's a US/CH version or a late euro F113B, and the voltage goes high enough, eventually the 10A fuse on the protection relay will blow -- as it should).
As usual, you're right on the money Steve. Voltage regulator had gone totally Charlie Sheen. The bearing was also squeaky so I just replaced the whole alternator. Pretty easy job to do, no more flickering, car is good as new again. Sincerely appreciate your help and knowledge, as always!
Glad that you got it sorted, and thanks for the feedback (it really torques my driveshaft when a symptom comes up for discussion, and we never find out what was the root cause).
Lol, I liked that one too...I've already used it twice in normal conversation. The value of Steve's contributions extend beyond the automotively technical!
