Faulty tail lamp wiring

[68mule]

Hey everybody, I'm in. i have been trying all day to post but there was some computer glich. I have an interesting situation in that my running lights no longer run, but all four lights come on when I hit the brakes. I recently had her painted. It used to be that the running lights worked, but the brake lights only worked when the headlights were OFF. So, something is happening at least. When I look at the wire diagram, it is significantly different than what is really there. Any thoughts? Thanks.

 

[Nut]

Welcome

Mule,

Welcome to the CAC. Are you the original owner? Was the wiring harness for the tail lights ever changed, replaced or have some "creative" work performed? Electrical circuits in this area are not complicated. S/b easy to ohm it out with a meter. Cheap at Radio Shack and required for elec fixes.

Start looking at the obvious. Call me kooky, but are the bulbs in the correct sockets? Check loose ground wires, dirty contacts. Make a fault tree. Work backward and ask us anything you may think regardless how small.

Lots of help here for the asking.

....... Nut

 

[68mule]

I have delayed this deal for fear of the belief that there has been some "creative wiring" for I am not the original owner. I'll go to radio shack tomorrow to get the meter. I'll double check the bulbs with Napa too. I think they only had one type of bulb listed for the car, but there has to be two different sets of bulbs right? I have dirt in my eye just from messing with the wires, so I'll check that. What's a fault tree? I bought this car to fart around with because I was a dumb jock in high school and didn't even put oil in my car back then. I have done all the work on it simply by reading manuals, please forgive me. Thanks

 

[Nut]

Fault tree

Mule,

My apologies. A fault tree is basically a simple block diagram. You start with a problem and run what is loosely termed a "tree" of possible faults that could cause the problem. As you check each out you cross them out but leave them showing. Allows you to see where you've been and see if there are similarities between what you've checked.

It's a good de-bug method used in the Engineering world. Also add any suggestions/solutions as you go. It's a living document. It may help, can't hurt. I'll talk to a couple "sparky's" when I get back from travel and see what they think. Worked before the paint job..... Hmmm.

Good luck....... Nut

 

[68mule]

I know a guy at Napa who has a 79, I think, he thinks I have a bad headlight switch. I also checked the fuses and one was burned out since the paint job. My fuse box contacts are all rusty, so, I am in the process of trying to clean those up, in hopes of a "simple" cure. I am trying to avoid the purchase and installation of a new harness, but we'll see. Thanks for your help.
P.S. They never worked properly before the paint job, just differently.

 

[ssvett]

Mule, Check all your grounds. They are "usually" the black wires that are conected to a bolt on the tail light assemblies. Also check the ground wire in front that is attached on you radiator core support on the front driver's side..............Good luck....Steve