1993 E36 325IS
Back story:
Car was in a wreck, rear end was damaged. No electrical problems after wreck. Car was repaired and then I noticed the gauges did not work. I figured hmm, the battery is just dead from not being ran in a couple weeks, I'll let the alternator charge everything back up. Alternator did not charge the car to the point of even turning over in a 20 mile trip. During this time the gauges pop up and down trying to work. I drove the car around for about half an hour or more and the battery came back up, still no gauges. Later that night I got back in the car and everything came back to life.
Since then:
A few days later I went out to the car and heard my drivers side window making noises, trying to go up and down. Of course the battery was dead if it had been doing this all night. I was quite puzzeled by this though because the windows in this model of course work without a key in the car, until the door is open to break the circuit after the switch is off, but this was after I had been out of the car and of course without a key in the ignition. I have no idea how the window motor and switch were getting power. Gauges are dead again after I get a jump. Battery and alternator tested: battery fine, alternator dead.
I replaced the alternator and battery comes back up, gauges are still dead to this day, a couple weeks later. Now on my OBC i've been using that to get a rough estimate for speed in kph but now the air temperature sensor is grounding out reading -34/-35 F and just today after I went and got the car inspected since that ran out in July, the range on my gas mileage is grounding out reading ---.
If anyone has ANY ideas please respond. I'm getting desperate I've had lots of people look at it that are friends and with a problem this weird I really am not in the mood to go pay $100 an hour to get it diagnosed. I have a full wiring diagram and to me it seems like when the alternator went it screwed something with low voltage in the main central computer. I'm not too knowledgeable about BMW's but I am an electrical engineer and this is baffling me.
P.S. when i say the gauges don't work, it's just the gauges - they seem to pop up and down at certain steady speeds, any sharp increases or decreases cause them to not move at all. All fuses have power and all fuses are good. odometer and engine lights are fine.
Thanks,
Garrett
Back story:
Car was in a wreck, rear end was damaged. No electrical problems after wreck. Car was repaired and then I noticed the gauges did not work. I figured hmm, the battery is just dead from not being ran in a couple weeks, I'll let the alternator charge everything back up. Alternator did not charge the car to the point of even turning over in a 20 mile trip. During this time the gauges pop up and down trying to work. I drove the car around for about half an hour or more and the battery came back up, still no gauges. Later that night I got back in the car and everything came back to life.
Since then:
A few days later I went out to the car and heard my drivers side window making noises, trying to go up and down. Of course the battery was dead if it had been doing this all night. I was quite puzzeled by this though because the windows in this model of course work without a key in the car, until the door is open to break the circuit after the switch is off, but this was after I had been out of the car and of course without a key in the ignition. I have no idea how the window motor and switch were getting power. Gauges are dead again after I get a jump. Battery and alternator tested: battery fine, alternator dead.
I replaced the alternator and battery comes back up, gauges are still dead to this day, a couple weeks later. Now on my OBC i've been using that to get a rough estimate for speed in kph but now the air temperature sensor is grounding out reading -34/-35 F and just today after I went and got the car inspected since that ran out in July, the range on my gas mileage is grounding out reading ---.
If anyone has ANY ideas please respond. I'm getting desperate I've had lots of people look at it that are friends and with a problem this weird I really am not in the mood to go pay $100 an hour to get it diagnosed. I have a full wiring diagram and to me it seems like when the alternator went it screwed something with low voltage in the main central computer. I'm not too knowledgeable about BMW's but I am an electrical engineer and this is baffling me.
P.S. when i say the gauges don't work, it's just the gauges - they seem to pop up and down at certain steady speeds, any sharp increases or decreases cause them to not move at all. All fuses have power and all fuses are good. odometer and engine lights are fine.
Thanks,
Garrett
