mystery short

Jul 22, 2005 Last reply: 20 years ago 5 Replies

I have a 1984 Bronco II that has a mystery short in the tail lights. Some times the fuse will blow out instantly when the light switch is pulled. Some times it won’t blow for a few minutes or hours. All the wiring that I can get to seems ok. I saw a lamp out module in the wiring diagram that has a resister wire in the circut before the module. Could these be causing my short? If so, where are they located?


THis is a 21 year old car and my guess is that the wiring in the car somewhere has insulation rubbed thru and it is touching ground, Check wiring under hood and were it goes the clamp and along its route to the rear.

That was my first thought too, so I disconected the harness at the connector for the passenger side light assembly and the short went away. I plugged it back in and the short was still gone, momentarily. So I figure that the short is in that part of the harness (connector to light assembly). I bypassed that part with a new wire, and the short was gone. I went for a drive and the short came back. That is why I’m suspecting the lamp out module, I don’t know much about them. Anyone ever have any experience with one?

On Thu, 21 Jul 2005 23:39:26 -0400, Bender rearranged some electrons to form:

I don't think you have found the short yet. Keep looking. It's bound to be somewhere where the wires and body are in close proximity. You'll probably have to inspect the entire harness.

"Bender" wrote: > That was my first thought too, so I disconected the harness at > the connector for the passenger side light assembly and the > short went away. I plugged it back in and the short was still > gone, momentarily. So I figure that the short is in that part > of the harness (connector to light assembly). I bypassed that > part with a new wire, and the short was gone. I went for a > drive and the short came back. That is why I'm suspecting the > lamp out module, I don't know much about them. Anyone ever > have any experience with one?

I fixed it, I ran a new wire from the switch to the light assemblies. Works like it should now.

Good job!!! You got it by process of elimination! Thats using your noodle. :D

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