I searched and could not find an problems similar to mine. My new body style f150 , all the rear lights have quit working.whats really odd is at first it was the left signal then the right then everything. All bulbs are good. If I pull the bulb out and test for voltage i get voltage, I replace the bulb and test again.....NOTHING. I took the rear ground off and cleaned it up, test fusses . Don't know what to do from here.

 

What year truck? I don't know what "new body style" means.

 

Sorry new body style 04

 

Anyone have a similar issue or have an idea where to start?

 

The first thing you need to do is change your troubleshooting technique. Then I think you can make some progress on your problem. I will try to hunt up a diagram also.

You need to use a testlight or leave the bulb in the socket and poke the wires with your meter. You have to keep or put a load on the circuit or you will get weird readings like you are now. A testlight is really the best way and they are cheap at Harbor Freight. They have a very sharp point on them also so it's easy to poke the wire, but with a testlight it presents enough load to where you could probe the socket like you are doing and get a good reading.

 

Here's a partial diagram of the rear running light circuit.

 

Thanks, I will do more checking.... Does the trailer receptacle run from the front or split off at the rear.... Tested trailer receptacle with test light and had power...

 

If you are using the official Ford tow harness, it comes from the front with it's own circuits and fuses. If someone added one of those aftermarket tee wiring harnesses, it's tied to the regular truck lights in the rear.