How to fix electrical problem? on 1994 Nissan Pickup (D21)

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When pushing on the brake pedal only the high mount comes on and the gauge cluster lights up same when shifting into reverse. And my tail light are very dim. Any ideas?
(1) Answer
(4) Comments
Brake light circuit shorted to the park light circuit. Wrong bulb, rusted bulb socket with poor ground, shorted wiring, moisture in tail light or if wired for trailer wires shorted there. I think when you shift to reverse, you also depress the brakes. Look at the rear lights first. All park lights are coming on when brakes are depressed! That is why dash cluster lights up as well. Remove both brake light bulbs to see if dash lights still come on with brakes pushed, post results for more info.
I'm not pushing the brake when putting it in reverse. It's a 5 speed I don't always have to. So what your basically saying is it could be a number of things wrong? I just need to go through a trial and error.