Alex E24 E30
07-24-2006, 11:09 AM
Just bought my 1st 6er, an 85 635csi euro. It's spent it's whole life in the States, and a good bit of the last few years sitting in a field. With a set of new crank sensors, the previous owner made it run, and I got it from him. The alternator in it was dead, and he replaced it with one from an E30, and that's the only electrical change that has happened to this car that I can think of. The problems that the car has are as follows:
Speedometer/odometer won't work (odo has a missing gear, I think)
Tach is finnicky at best, and cuts in and out corresponding to any
electrical interference (i.e. turn signal, windows, braking, sunroof)
Fuel gauge did work, but is now dead, temp gauge has never worked
Aftermarket radio turns on and off from the same interference as tach
In trying to diagnose the problem, I discovered that when the key is in the run or start position, the only thing that charges at 12.5+V is the alternator. Headlamps, power distribution box, etc. only charge at 9.5V. I understand that the alternators in the 3, 5, 6 were interchangeable, and that if an alternator had any problems, it either worked or it didn't. Of course, at only 9.5V, headlamps and taillamps are very dim, and slightly hazardous at night. Could it be that the speedo and other gauges are dead because of this low voltage? A look at the SI board itself showed signs of having been wet in the past, possibly acid damage as the source seems to be from where the batteries are located. A new SI board/cluster wouldn't hurt anyway, but I am curious as to the answer.
Thanks in advance,
Alex
Speedometer/odometer won't work (odo has a missing gear, I think)
Tach is finnicky at best, and cuts in and out corresponding to any
electrical interference (i.e. turn signal, windows, braking, sunroof)
Fuel gauge did work, but is now dead, temp gauge has never worked
Aftermarket radio turns on and off from the same interference as tach
In trying to diagnose the problem, I discovered that when the key is in the run or start position, the only thing that charges at 12.5+V is the alternator. Headlamps, power distribution box, etc. only charge at 9.5V. I understand that the alternators in the 3, 5, 6 were interchangeable, and that if an alternator had any problems, it either worked or it didn't. Of course, at only 9.5V, headlamps and taillamps are very dim, and slightly hazardous at night. Could it be that the speedo and other gauges are dead because of this low voltage? A look at the SI board itself showed signs of having been wet in the past, possibly acid damage as the source seems to be from where the batteries are located. A new SI board/cluster wouldn't hurt anyway, but I am curious as to the answer.
Thanks in advance,
Alex