I have a 2004 7.3L. When I hook up the trailer the turn and stop lights do not work. What can I check. It works when I hook it up to my Tahoe????

 

Try Double checking your connections https://www.ford-trucks.com/forums/5...g-diagram.html .

 

which plug are you using

 

7 way plug.

 

have you cheched for power in 4 way
had a problem where harness was plugged into back of 7 way being corroded

 

I seem to have power. the running lights work and the rear trailer lights work. They just don't blink or brighten when the signals are used or brakes are hit.

 

I understand that but does signals work at 4 way plug

 

I am not sure. I do not have anything that plugs into that. I guess I can take some reading with a meter. Thanks..I'll update tomorrow

 

your heavy duty flasher module is burned out. It is in the powerblock under the hood, not the fuse block under the dash. It is a cube type plug in module. refer to towing supplement included with owners manula and it will give you a diagram. I am in my jammies now or I would go to my truck and tell you what the number on the mudule is. I had the same problem a cpouple of weeks ago and its like a $5.00 fix.

 

Thanks for the help guys...I'll try it and let you know.Night

 

Does the orange wire on the back of the truck plug have power to it,...Mine does Not.
I found the realy you were talking about and I am getting one tomorrow morning. I'll let you guys know if it works.

Thanks