My check engine light doesnt light up ??

[Adrian_Visser]

So what car is this you have? Year?

[Todd Black 88]

If its fuse 10 you blow, pull the shift gaiter back and look at the wires that go through there and feed the reverse light switch in the tranny.

[Adrian_Visser]

The voltage should be around 14v when the engine is running so no problem there. It seems weird that all these things are going at once I mean the blower and gauges are on separate circuits with separate fuses.

Anyway I would start b having a look a tthe wiring diagram available here:

http://www.wedophones.com/BMWManualsLead.htm

[10yre30r]

Wow , Todd its amazing your asking me that about the reverse light switch. Yesterday as i was testing and troubleshooting i put in a good fuse in the box turned on the car ...as usual everything is fine. The second i put the car in reverse without even putting the car under load at all the fuse blows. I drive a 325is 1988. Fuse #9 is my injection electronics. My (red) check engine light is now on. I guess i must have screwed up a sensor through all this and my idle is low (300-400) and bouncy. I accelerate and it comes down real low like 200 then it goes up to like 3-400. Im gonna hunt down that reverse light switch in the tranny . Is there something i should look for when i find it or should i trouble shoot it in some way ?

[10yre30r]

I apologize it isnt #9 its fuse #10 ...my eyes are a little fuzzy at times.

[Todd Black 88]

Wow , Todd its amazing your asking me that about the reverse light switch. Yesterday as i was testing and troubleshooting i put in a good fuse in the box turned on the car ...as usual everything is fine. The second i put the car in reverse without even putting the car under load at all the fuse blows. I drive a 325is 1988. Fuse #9 is my injection electronics. My (red) check engine light is now on. I guess i must have screwed up a sensor through all this and my idle is low (300-400) and bouncy. I accelerate and it comes down real low like 200 then it goes up to like 3-400. Im gonna hunt down that reverse light switch in the tranny . Is there something i should look for when i find it or should i trouble shoot it in some way ?

Just look at the wiring under the shift boot.

Alot of the time the wires rub on things under the car, and wear off the insulation. Then it bumps against the chassis somewhere and shorts out, blowing the fuse.

There is a plug for it under the shift boot, and the wires run through the rubber seal under the shift boot. Find the plug that feeds those wires and disconnect it. If it doesn't blow again, you found the source.

[10yre30r]

Thanks Todd . I disconnected the plug and no more blowing the fuse . I drove the car around and nothing. Its perfect. All the the lights and guages work including the blower for the A/C . My yellow check engine light blinks normally as you start the car and after you press the brake it turns off just like it should. The (red) check engine light was on. So i disconnected the battery and reconnected it shortley their after and it hasnt turned on. The idle is very stable at about 550 without the bounce. Which is where i had it before it was giving me the low and draggy idle. I just want to thank you and this awesome Website....:) . I used to be a faithfull member of the bmwe30network until it simply vanished. Ive found a new home. Thanks.