tested all things with the relay and fuse box today and all passed still no running lights.

 

Fireman - I'm bothered by what you're NOT saying, so I'm going to ask you a simple yes/no question: If you turn the truck's parking lights ON, and probe the trailer connector pin at 11:00 o'clock with your voltmeter positive lead and the pin at 7 o'clock with the voltmeter negative lead, do you read battery voltage?

I f the answer is no, the fault is in your truck's circuit, and you've eliminated some potential trouble points already. But, if the answer is yes, then the fault is in your trailer wiring.

- Jack

 

What covers all things with the tests ?

One of the tests above is check continuity from the trailer tow parking lamp relay normally open terminal to the rear of the truck.

 

sscully, i did all the test that you listed yesterday for me to do with testing the relay pin sockets for power and ground in the fuse box. they all passed. I went under the truck and the wire harness plug above the rear axle (main harness from front to rear) where it goes from that plug to the tail lights and the trailer connection plug I have a wire at the main plug above rear axle that is hot when i turn my lights on and it goes up towards the drivers side tail light but nothing coming down to the trailer plug is hot with the lights on only turn signals is hot. If i trace the parking lights wire back from the trailer connector to the plug above the rear axle i have no power at each side of the plug for that wire.

 

What happened with the continuity tests ?

This was one of the tests from the relay socket to the back of the truck.

This is the open item to move forward.

You keep looking for power from the normally open pin in the relay socket at the trailer tow adapters ( 4 or 7 ), but you don't know if this wire is good.

Right now this is the only thing to check.
You have:
- Power to the relay socket on the common terminal
- Ground on the relay coil
- Power from the parking lamps to the trailer tow parking lamp relay coil.

If you put a known good relay in, you know the relay is not the cause, so it is either the wire front to rear, or the terminals in the trailer tow adapters ( hard to believe both are bad ).

Not sure what you were testing in this connector :


This would be a Brown w/ White stripe wire in this connector to the trailer tow adapters. pin 15 in the connector )

The truck's parking lamps is a brown wire ( splice under the rear bumper for both L&R tail lamps, and for the license plate lamps ). pin 5 in the connector.