'85 dash lights dim....no interior/dome light either

[sandyshores]

Hey all,
I bought this F150 about 2 months ago and thought that maybe it was just due to the age, but the dash lights look to be permanently dim. The dimmer switch does work though, while the highest setting isnt very strong at all. I read in one of these F150 forums about someone with a similar problem but cant find the thread. Oh well. Ive taken the dash out and changed out 2 bulbs and even took off one of the blue plastic coverings to no avail.

On top of this is the fact that one the lights are on and I turn the knob hard over to the left to activate the interior lights, the dash lights go out alltogether and I get no interior light. I used to have the dome light go on before so this is something new, and I believe unrelated to the 1st problem. Ive disconnected the wiring harness that runs down the floor and under the kickpanel and back under the seats as I thought there was a short in it, but the problem still exists. Any suggestions?