Evening all.
I have an 03 f150 (basic model, manual transmission, extended cab)
I noticed that my trailer lights dont work. Went down to the neighborhood mechanic, and we tested the fuses. They looked fine, but we noticed that they are only getting .13v, when they should be getting around 12?

He has no idea what would cause it, and said he would ask his other (a real ford) mechanic if they know. In the mean time, he told me to ask around on here.
Any ideas?
Thanks

 

Where are you measuring the voltage ? At the fuse itself , ? Or the plug ....

 

We tested both. (plug for trailer lights, and fuses where you can attach meter o top of them)
There is two fuses (left and right side of trailer) one side is getting enough, the other is not.
The ground seems to be in tact just fine. and there seems to be no altercation to the wires themselves.
We tried to test the port where the fuse goes, but our meter was to thick to fit in..

 

So , you checked the fuse tops in the fuse panel . One side has battery voltage , the other side of the fuse top does not ... correct ?
That would be a blown fuse , If I understand what you describe .
Pull the fuse and check them .

 

We checked both fuses. Replaced one then checked again. They're fine

 

Use a paper clip or thin wire to probe and check with your meter .

 

your on fuses 19 and 20 ? Both are 10 amp ? The input side of both should be 12 v. They get power from the same breaker. If there is no power into 1 fuse then the backside of the block might have a problem. If you have power into both fuses, and not out of one fuse, then the fuse or the holder is problem.

I would jumper power to the fuse from another source and see that all wiring and lights to the trailer work, then go from there.

 

Did your mechanic friend check his meter on a known circuit? If so as others have suggested start where you have power and work your way down the line to find the break.