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1992 headlight power runs thru the Muliti-function switch(turn signal switch) on the steering column
So when you turn on the Main light switch the 12volts for the head lights runs up the steering column thru the multi-switch and then back down the steering column, out thru the firewall and to the headlights.
Headlight switch---------------multi switch---------------head lights
And the multi switch also switches low/high beam so if those are acting up then problem is most likely in multi switch.
Ford used a Brown wire for parking and license plate lights for many years, tail light Brown wire should be drivers side frame rail at the rear, rear license plate light would be spliced in there.
Over the years people add or change trailer light connectors, so these wires can get chewed up, follow any current trailer light plug to where it has been spliced
The tail lights usually share 1 Black Ground wire, it would be bolted to the frame near the other tail light wires, but brake and turn lights would be on this same ground, so if they work then it should be good.
There should also be a Ground strap in the engine bay that goes to the Frame, that's the ground for the tail lights, also a ground wire that goes to Radiator support, that's the ground for the headlights
Last edited by RonD; 10-02-2016 at 04:29 PM.