So I started the car up yesterday and it was all fine and well. I turned on the fog/running lights and I started to drive down the road. About 5 miles down the road I hit a bump and the fuse blows and the fog/running lights go out and the dash dims down. This wouldn't be a huge issue with the exception that it knocks out the tail lights too. They still light up when I hit the brakes, but if I'm not mistaken it's dangerous and illegal to drive without tail lights. The fuse that it keeps blowins is the 10 amp "Tail" fuse. If I replace the fuse it wil all work just fine until I hit another bump. I put new grounds in for the lights and cleaned up the other grounds, but I'm not sure where to go now. I had the dash rebuilt a few weeks ago, but it seems so typical with this car that as soon as you get one thing fixed something else goes. So any input that y'all can put in would be great and I'm open to trying anything.

 

Sounds like a wire is shorting to ground somewhere for sure. Did the problem "just" start after the dash rebuild or was it there before? If the problem "just" started the dash rebuild is your most likely culprit.
Your ground short is occuring before it ever reaches the bulbs.....maybe check the wires that go to the fog light switch in the dash area. Hard shorts are easy to find...intermittent shorts are not so easy.

 

spell corroded wire junktions.deep under center of dash . Big soildered wires attack the smaller off shoots from the flux that is used , Hide the saw-zaw befor attempting this advanced procedure .

 

It is common for tail, front parking, interior, and instrument lights to be on the same circuit. As you noted stop lights are on a separate circuit.

I would be looking at the light sockets and wiring first. Make sure the sockets are in good shape and the bulbs are properly seated. Then see if the wiring is intact. Chances are it's just a bare wire touching metal somewhere.

 

I had to laugh when I saw that you edited this for spelling.

 

still lookin around. i checked out the light sockets and theyre ok, the light bulbs are new. i cleaned up the grounds and its not happening as often, so maybe i still have a few more grounds to find and clean up. i really appreciate all of the input guys

 

My 85 blows the same fuse if I use my tilt wheel. I clearly dont use my tilt wheel. But i do need to fix this some day. Seems like we need to trace the entire route of the wires. I would assume my problem is in the steering where a wire is moving?

 

It is not a bad ground that is making your fuse blow, it is an extra path to ground that is making it blow. Somewhere, definitely before any bulb in the circuit there is a connection (undesired or unintentional) to ground and that path is conducting more current than the fuse is good for.

My experience with shorts is that they are usually man-made. In other words, while anything is possible, usually they are a result of some work that has been done on the car and the wiring not put back in just the right way.

There are several ways to find a short, there is some fancy equipment that puts radio waves into the wires and makes them a big antenna and then you go around the car with a little receiver and find the short that way. You can disconnect all the circuits on that fuse and connect them back up one at a time until the fuse blows and narrow it down that way. This is hard to do on a car because most of the wiring is not easy to disconnect without cutting it.

The last time I had a short, I got a small buzzer at Radio Shack and connected it across the fuse. As long as there is a short, the buzzer will buzz. Some people use a light to the same effect. Then go around the car moving all the wiring, especially in areas where there has been work done and get the buzzer to stop buzzing. If it is an intermittent short, do the same thing, except now you are trying to get the buzzer to buzz, to simulate like when you drive over a bump.

There is always some luck involved in finding a short..............

 

good to know, that may help me since I think the problem is under the dash, where the alarm was installed with door lock remote