Tail light snafu

[cozee]

Lost my tail lights on my '88. Fuse is good (Also try them with a new one), switch works (tried a new one here also), but no tail or dash lights. If I power them through the trailer plug all is well. Any ideas before I start looking later this week end?

[Pete M]

When I lost brake lights in my 88 it was due to corrosion in the wire harness connector located behind the drivers side rear tire.

[cozee]

But I am getting power back up to the switch because I get dash lights also when I power the circuit through the trailer plug.

 

I don't have a schematic but am guessing maybe a wire problem coming out of the fuse block.

[carnuck]

It could be corroded at the fuse, and cutting power when the lights draw. Kind of like a loose battery terminal works till you hit the start switch, then it cuts off till you let go of the key.