I am in France where I work for the moment, and I have a problem with a 1991 convertible with an M40 engine that I know someone can help me with. ÂwafflesThe E30 m40 convertible which I bought here because the weather and landscape are made for it has a chronic problem of draining the battery because the power windows are somehow wired to a non-switched circuit, and the little lights on the switches drain the battery after a couple of days. This is not my problem — IÂ’ll get to that. Since I am not good at electrical stuff, Âwafflesmy solution was simply to cut the circuit breaker for the windows. But yesterday I decided to take a look at junction C302 behind the steering column where the windows wiring is supposed to be connected to the fuse box. ÂwafflesI removed the positive battery cable and took off the panel under the steering column and had a look : the window wires are not at C302. I put the battery connector back on and begin pulling fuses in order to find out which circuit the windows are on — it turns out that they are on fuse 28, the cigarette lighter and the antenna motor circuit. However while looking at C302 I had unhooked a red wire which looked like positive lead to the radio which was attached loosely, so I replaced it and turned the ignition key to on to see if the radio would go on.
Surprise. Not only is there no radio, but the instrument panel did not light up.ÂwafflesThe engine turns, but does not start, of course. Is there a cause and effect between what I did and the loss of ignition : who knows ?
Anyway I have pulled out my Bentley, and my pdfs of circuit diagrams. I am not good at electrics but I can follow a flow chart. I have power to the ECU connector pins 18 and 37, and the main relay clicks when I ground the connector 36. I can also run the fuel pump from the connector .
I have checked the pins for the main relay. I have no power to pin 30 our 87. Bentley says to check the big red wire from pin 30 to the battery junction on the firewall, but I cannot find this junction. The wire enters a loom that goes into the firewall in front of the glove box.
This is where things stand for the moment. I would be very grateful for any advice, referrals to previous posts – anything and everything ! But in particular, does anyone know where to find the battery junction where the BMW wiring PDF shows the lead from pin 30 on the main relay connecting with rd lead to the ECU, fuel pump relay, etc.
Sincerely
John in Montreal (well in France for the moment)
Surprise. Not only is there no radio, but the instrument panel did not light up.ÂwafflesThe engine turns, but does not start, of course. Is there a cause and effect between what I did and the loss of ignition : who knows ?
Anyway I have pulled out my Bentley, and my pdfs of circuit diagrams. I am not good at electrics but I can follow a flow chart. I have power to the ECU connector pins 18 and 37, and the main relay clicks when I ground the connector 36. I can also run the fuel pump from the connector .
I have checked the pins for the main relay. I have no power to pin 30 our 87. Bentley says to check the big red wire from pin 30 to the battery junction on the firewall, but I cannot find this junction. The wire enters a loom that goes into the firewall in front of the glove box.
This is where things stand for the moment. I would be very grateful for any advice, referrals to previous posts – anything and everything ! But in particular, does anyone know where to find the battery junction where the BMW wiring PDF shows the lead from pin 30 on the main relay connecting with rd lead to the ECU, fuel pump relay, etc.
Sincerely
John in Montreal (well in France for the moment)