Out of no where fuse #12 blows as soon as ignition key is first turned. Brake lights and turn signals etc gone. Now to find the problem and short. Ugh. The Vintage is a few days away……
Fuse #12 Blows
- Thread starter Mot27cars
- Start date
If you've been putting things in the trunk check the wiring that runs along the back end to the light housings and all the connections there.
i recall my car has only 10 fuses, is that possible ?
This is on an e3. And the fuse is blowing immediately. Before the engine is started, and no brake or turn signal or anything is applied.
Attachments
Are brake lights and turn signals on the same fuse? Can't remember. Might start with the ignition switch.
Immediate blown fuse is usually a short to ground. Pull the fuse and check whether you have continuity to a body ground under the dash. With an e9, the downstream elements of the circuit would be tested on the lower of the two fuse connections - I assume the e3 is the same. If you find continuity to the body at that connector, you have a direct connection to ground somewhere in the fuse 12 circuit.
If so, first step is to determine if anything in that circuit was on when you started the car (you may have your backup lights on if you routinely start the car in reverse, for example). Check that stuff first. If not, then you likely have a short to ground between the fuse block and a switch or in one of the switches themselves.
If you could post what's in that circuit I could provide some more specific suggestions. As Steve notes, if fuse 12 is a light circuit, the tail light assemblies are a likely trouble spot.
If so, first step is to determine if anything in that circuit was on when you started the car (you may have your backup lights on if you routinely start the car in reverse, for example). Check that stuff first. If not, then you likely have a short to ground between the fuse block and a switch or in one of the switches themselves.
If you could post what's in that circuit I could provide some more specific suggestions. As Steve notes, if fuse 12 is a light circuit, the tail light assemblies are a likely trouble spot.
Yes they are
I had a loose 5w city light grounding under the headlight bucket. It caused the the driver side turn signals to blow fuses immediately.
Hope it's a simple fix.
Hope it's a simple fix.
my mistake
thank you for educating me in the e3 specifics
Well culprit appears to be the reverse light switch on this getrag 265….
Was all back together earlier this afternoon and went for a ride.
Repair manual wiring diagrams are your friend.
Repair manual wiring diagrams are your friend.
As usual, input from this Forum is invaluable. Even if not experiencing this very symptom, the feedback and suggestions based upon decades of living with BMW E3/E9 foibles, is educational and so helpful. Glad you found a solution, and also for posting so that others could post their ideas.
Yes! The input from all these members is always appreciated and invaluable!!!
I’ve said since my beginning, that I’ve never been associated with such an awesome group of people on a forum!
So glad you found the problem & were able to get it resolved & fairly quickly too.