Jump to content
ATLBMW

What have I done? Electrical question

7 posts / 538 viewsLast Reply

Recommended Posts

My right side tail light kept going out, and I realized it was because the plastic housing (in the trunk) was broken. I superglued it back together, and put a c-clamp on the housing to hold it together while the glue dried. I decided to see if I had fixed it, and mistakenly turned the lights on while the c-clamp was still attached.

The c-clamp was touching both the positive and negative side of the light fixture (Doh!), and the lights quickly faded out (along with the license plates lights and front right parking light (all on the same fuse). I was hoping that the fuse simply burned out, but after replacing the fuse the lights still don't work. Then, I thought maybe the bulbs all burned out, and tried switching one in from the left side, but it didn't work on the right (and then did work again on the left).

What else could it be? Please tell me I didn't melt a wire somewhere along the way...

Share this post


Link to post
Share on other sites

circuit is trashed. Presume you replaced the fuse...and still nothing on that circuit.

First thing I'd try is disconnecting the wire from the offending tail light bulb (the one you just repaired and shorted out), stick in a new fuse and see what happens. If things light up, then the old socket is messed up--you'll either have to replace the tail light bulb housing (someone on the board will have a good used one for you), or buy an aftermarket socket at the auto parts store and graft it in place.

If you still have no lights, then you're gonna have to trace down wires with an ohmeter (circuit dead) to find a broken wire. Hopefully the fuse blew quickly enough to protect the wires (as it's supposed to) and it's only the original (repaired) socket that's the problem...

Let us know whatcha find...

mike

Share this post


Link to post
Share on other sites

Okay I tried this: I unplugged the wiring harness for ALL of the lights on the rear right (turn signal, back up, etc. included), replaced the fuse, and turned on the parking lights. The front right parking light (which I understand is on the same fuse as the right rear parking light and license plate lights) still didn't come on.

I replugged in the wiring harness on the back right and am back to where I was - everything on the car works except those things on the line of fuse #2.

Any other thoughts before I have to follow the wiring and look for a burned area?

Share this post


Link to post
Share on other sites

the fuse that originally blew when your C-clamp shorted the circuit.

Then disconnect everything that is served by that fuse, and re-connect each item, one at a time, until the fuse blows again.

When it does, you've found the problem circuit.

cheers

mike

Share this post


Link to post
Share on other sites

this is where a electrical meter comes in. Check to see what your missing positive of negative potential.

Share this post


Link to post
Share on other sites

Okay, found the problem. The fuse terminals in the fuse box are mismanaged, and through some trial and error, I have figured out which fuse really goes with which systems. The one that was for the right rear taillights and license plate lights is supposed to be fuse #2, but in my car it has been moved to fuse #8.

I looked at fuse #8, and sure enough, it was burned out. I replaced it and the lights know work.

Now I am determining which fuse is which, and when I get it all figured out I will fix all of them by removing the fuse panel and making the adjustments.

Right now I am having trouble determining if the rear window heater is on or off - will probably have to go back there with a tester. Also, it looks like there is supposed to be separate fuses for the right turn signal vs. the left turn signal, however mine seem to both be on the same fuse...

Thanks for everyone's help!

Share this post


Link to post
Share on other sites

Apparently you don't have a fuse diagram on the upper, left of your hood (trailing end). Both the ones on my '75 and my wife's '76 show that #8 was the fuse serving those lights.

You can get replacement fuse diagrams from La Jolla Independent (www.bimmerdoc.com) or, I believe, tilux (Site Search on this board for contact info) may have them as well.

Since fuses are ALWAYS the first thing you should check when experiencing electrical problems I think a fuse diagram is something you'd want to have.

Bob Napier

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.




×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.