Dashlights not working

[albany9044]

Hey none of my dash lights are working, i mean the speedo ones dont work, the ones on my windows switches dont work, the one on my HVAC dont work, literally nothing. Ive already tried replacing the headlight switch to no avail. Tested the wire that controls the dash illumination with the headlights on and it had power. It has an aftermarket stereo and i tried it with the stereo unplugged and still didnt work. Also made sure the illumination wire wasnt exposed or anything. Oh and another thing is that it blows the fuse immediately as soon as i turn the headlights on. Fuse #18 5A

 

[stamp11127]

Welcome to Electrical for Fords 101.

You'll need at least a dvm to troubleshoot where the short or excessive load (that) is occurring unless you are able to spot it visually. You will need to trace the harness looking for a spot that has grounded to the chassis.

 

[bedrck46]

how long has this problem existed.

If this is a recent problem, have you done any work to any of the switches etc, or overhead assembly that may have caused the problem.

In other words have you done or made any repairs lately

 

[albany9044]

how long has this problem existed.

If this is a recent problem, have you done any work to any of the switches etc, or overhead assembly that may have caused the problem.

In other words have you done or made any repairs lately

its been since i bopught the truck which was a little over a month ago


how can i use my volt meter to do that?

 

[bedrck46]

prints attached

 

[stamp11127]

After looking at the prints this one make take some work to find. Can you understand the prints and trace wires? I'm only asking so that I'll know how to explain the steps involved since you will be "tearing" into the harness. You will also need to make a jumper wire to isolate what branch circuit the problem is on (length tbd) and a bunch of fuses or a type 1 or 2 circuit breaker.

Was the replacement headlight switch a new one?
What is your Expys year?
What brand & model meter will you use? I'll try and get a manual for it.

 

[bedrck46]

prints

 

[stamp11127]

We had the same thing happen on a school bus and spent hours looking for a short. Couldn't find it - then started thinking about what haven't we checked.

Would you think a burned out light bulb would cause a fuse to blow? Well they can, if the wire melts and drops on the other electrode you now have the short. Had to see it to believe it.

Check the headlight bulbs just for giggles. If it has happened you will be able to see it. Do not touch the glass, if you do, wipe it with alcohol to remove the oils or it will overheat.

 

[ydopen]

are the parking lights working?

 

[albany9044]

yes my parking lights are working, mine is a 98 and im not sure the model number of my multimeter, i will check when i go back out to the car. and no the switch wasnt new, i bought it off ebay