Have a 1994 Dodge Ram 1500 4x4 1500 with wiring problems. The original problem was a brake light out on the drivers side. I changed the tail light plugs. With head lights off I had brake lights with head lights on no brake lights. I noticed the trailer wiring was worn out broken wire etc. I cut the trailer wire off at the plug and removed the trailer wiring. There were 2 wires that ran from the plug to the engine area 1 was red and 1 was blue. The red was not hooked to anything the blue went into the firewall and Im not sure if it was attached to anything. Now the problem is the truck will not start at all. The starter turns but engine doesnt fire. Ther are no passenger side tail lights. Also the brake and ABS lights are on. My Question is. Is this all because of cutting off the trailer wiring? And I would like to know where the blue and red wire should be connected? Any help would be greatly appreciated.

SOURCE: 04 DODGE RAM TRAILER BRAKE WIRING

If you have a seven pin connector in your tow package, you should be wired for electric brakes. just need the brake box.usually in your owners manual it will show you where to plug the box into. the best thing to do is contact your local chrysler dealer and ask them.if you give them your VIN number they should be able to tell you for sure.

SOURCE: 02 RAM 2500 no power at trailer plug

It should have a fuse for the marker lights. Do they work on the truck. Brown is the color for the marker lights. Good Luck

SOURCE: factory 99 dodge trailer plug wiring

You'll need to disconnect the wires from either the truck connector or the trailer connector...
I highly suggest purchasing a voltage checker- it looks like a screwdriver with a pigtail of wire with an alligator clip on the end. The tip of the 'screwdriver' has a point for probing. The light in the probe will light up...makes it easy to trouble shoot without a helper behind the trailer.
Hook the aligator clip to a good positive grounding point on the bumper or frame(not painted).
then pin by pin on the truck connection, stick the probe on each terminal tab.. and write a simple diagram where you find brake, tail, backup, etc...
Then i'd suggest, taking the connector off of your trailer, exposing the wire ends.
Run again thru your diagram and turn on each light of the truck. As you do, touch the wires from the trailer to that specific terminal. (make sure your ground wire is attached on the trailer) you can mark each wire with a piece of tape and label it which is which.
then simply attach your trailer wires according to your diagram to the terminals in the connector... that should get you in business..
hope that makes sense...
That way if the factory wiring harness remains the same, you'll be able to use it with other trailers if the need arises..

SOURCE: LEFT TRAILER TURN SIGNAL DOES NOT WORK

I have seen once before that the fuse box was bad on a 2003 Dodge 3500. I had power in and nothing out. We had to replace the box. Not cheap! Hope it is simple like a loose connection though. I think I had to pull the inner fender on the drivers side to access the bottom of the fuse box. Pain in the ****, but...

SOURCE: abs and brake light stay on

check again the connections and that it is clipped on to supports correctly -also check the wires may have damaged or frayed one of the lines