Author Topic: Blowing fuse #11 (Read 4486 times)

Wizard · « **on:** September 30, 2006, 01:05:29 PM »

I keep blowing fuse #11 (Labeled-"Injection Electronics").
It does not happen immediately after starting the car. Usually after driving atleast a few miles it will blow the fuse. I have installed a new fuel pump and have changed the fuel pump relay thinking one of those may be bad. The voltage at the fuse (while car is running) only shows 11.8 volts while other circuits are showing around 12.2 volts. Anyone have any other idea at what may be causing it to blow. It can not be a dead short as it does not blow immediately. Does anyone know what other components are running through this circuit?

Thanks,
Dan

1991 318is M42

FL318is · « **Reply #1 on:** September 30, 2006, 08:30:04 PM »

Do you have the owners manual? Dumb question but I was amazed at how the fuses where cross connected. I blew the trunk light and the Tach quit working!!!!

I have no solutions but if you get no answers I will ask my tech on Monday.

Wizard · « **Reply #2 on:** October 01, 2006, 09:39:27 AM »

Another weird thing.....I tried changing out my ECU to a spare one I have (stock chip) and now my voltages all read higher...13.8v on all circuits (at the fuse box) EXCEPT the fuel pump circuit which is at 13.2v...Not sure why the "chipped" one would read lower....Maybe I was just getting bad readings.....
Nontheless, the problem still persists even with a different ECU. I also checked the voltage at the pump itself and it is reading 13.8v....Not sure why it would be lower at the fuse box...
I haven't changed anything electronically lately. The car actually runs great otherwise.
Maybe I'll just throw a 30 amp fuse in there and see what starts smoking first...J/K....lol

tmorinbmw · « **Reply #3 on:** October 01, 2006, 05:57:23 PM »

the starter exciter wire has been B/Y (black with yellow stripe). So that being said and according to my factory wiring manual for a '90 325i/is, fuse 11 (7.5 amp) is terminal 87 on the fuel pump relay (green and violet wire) which when turned on thru the ECU and main relay is provided power by the 1.5 mm red wire at the battery junction block which is on the fusible link wire not the battery cable. You could have a corroded fusible link causing voltage drop.

Just my two cents, good luck!

Jtuner · « **Reply #4 on:** October 01, 2006, 10:44:20 PM »

I'll check alldata for you when I go to school tomorrow and let you know everything that's connected to fuse #11.. Things like this are usually dumb and easy to fix

achtungE30 · « **Reply #5 on:** December 17, 2006, 08:20:25 PM »

Well i'm not sure how related my problem is to this one...but I keep busting fuel pump relays...

THe fuel pump is brand new since june 2006, i replaced the relay twice...
Fuse #11 is fine but I replaced it anyway.

Just sucks I would drive the car a few miles, park it for a day then it wont start...each time this happens, usually when it sits a day or a few days.