I came across a 87 ford f150 with a 5.0 and im currently having an electrical problem and cant figure it out for the life of me. I have no headlights, taillights, no interior lights what so ever, no horn and no buzzer unless i turn the key but turn signals do turn on and brake lights will light up when pressed i also have radio which also will turn off when the light switch is pulled i went through all the ground wires and made sure they had solid non painted surfaces and replaced the bad frayed ones on the block to the body. Its happened before and i could just leave the light switch pulled out and sometimes after a few hours everything would work again and i have replaced the light switch with a new ford one also is there anything else that im missing? i could check to see if im gettin power to everything but id have to wait to get my multi meter from work anyone else have any ideas? cause i also tried wiggling the wires under the dash to see if there was a short and found nothing either

 

Check the fuseable links under the hood near the battery, may have one burned, replace with the same type as well, NAPA or equivalent should have them.

 

Might be a situation where mice had a field day with either the harness behind the dash or in the engine compartment.

Your gonna have to get eyes on every inch of wire for both to verify there's nothing shorted out.

 

I'll give it all a look and see in the morning, as far as i could tell though i seen no bad wires persay whoever put the engine in turned the wires into a "rat nest" and ill just have to follow everything to their source