trailer harness problem

[redskins]

hello,
hope someone can shed some light on my problem.
I was working on my utility trailer wiring and had the 4 pin harness hooked up to the truck so I could test my trailer lights.
My problem was that only some of the running lights were working. As I was checking all the spots were the wires were tapped together they went out.(they actualy went out as I removed a bulb that was not illuminated). So I put the bulb back in and still no lights.
I took my voltmetre to the 4 pin connector at the truck to test for current and found that the left and right signals were recieving power. however when I tested for current in the running light slot it was dead?
how could this be?
I cleaned the contacts and still no power.
how can only one slot not work,,, if i shorted something out should not a fuse have blown? and if a fuse blew then how can I be get power to the left/right lights????????
help.
2003 FX4 5.4

 

[rwinch]

Refer to your factory manual, or get a Haynes or Chilton manual for your truck. You will find that the running lamps are powered and fused seperately from the turn signals.
From the schematics I have for my '98 EB, the running lamps are power and fused through the Power Distrubution Relay Box which is located in the engine bay, drivers side. Yours may be in a different location.
In any case, a brief inspection of the fuses will show you which one has blown, you just have to know where to look, hence the need for the manual(s). Also, the owners manual should have them listed.

 

[redskins]

rwinch

Thank you for your reply
One of me three sons shoved my manaul under the rear seat and I found it after posting my problem
you are correct, my fuse panel has a fuse for trailer running lights and some kind of relay for the same lights. I am assuming they did this so you wouldn't lose you truck lights as well as your trailer lights should a SHORT occur.
will look at my problem after work

thanx again

skins