Hey how are you guys, I've searched all over but havent found an answer so here I am. I have an 88 f150 4.9 and my headlights, tails, dash, interior, and radio won't turn on. I replaced the switch and pig tail and still nothing. I had the red,brown,and yellow wires together and my head and tail lights worked fine, but with the whole switch plugged in nothing works. Also all of my fuses are good. Any help will be greatly appreciated. Thank you

 

Have you checked the fusible links on the starter solenoid? They are the small wires that are on the same post as the battery cable.. Just give them a little tug, if they stretch they are burned out, if they don't stretch they "should" be good.

 

Do you mean the radio won't make noise or that it won't light up?

Big difference in terms of diagnosing an electrical problem.

 

White, no i did not check the fusable links. I didn't even think of it thank you. And the entire radio won't power on. I'm going to re check all of the ground wires and links. Thank you guys.

 

The Black/Orange wire fusible link at the Starter Solenoid
(same lug as where the Positive battery cable attaches to the
starter solenoid) provides the 12 volts for the Headlight switch.
If the cigar lighter doesn't work the fusible link is probably blown.

 

It's weird. Because I have the red, brown, and yellow wires jumped over to a switch and my head/tail lights work. It's just when I have the actual switch plugged in nothing works. Just from looking all the links theyre ok but i didn't have a lot of time so ill have to check again this week.

 

To verify if the Black/Orange fusible link is good.
Push in the heating element for the Cigar lighter.
If the Black/Orange wire is supplying 12 volts
to the Cigar lighter the heating element will pop
back out in 15 seconds and the element will be hot.

Or plug in an accessory that uses 12 volts.

The Headlight switch only has these colored wires.

1) Black Orange Hot all the times. (This is the main 12 volts for the Light Switch).
2) Tan/White Provides 12 volts for the Brown wire for the
Exterior lights
3) Orange/Black for Radio
4) Light Green/Yellow for Cargo lamp
5) Red/Yellow for Headlights
6) Brown for Exterior lights
7) Light Blue/Red for Radio, Heater, Ash tray, Instrument panel and wiper lighting.
8) Yellow/Black for Radio
9) Black/Pink for Courtesy lamps Map, Dome lamp