Too many wires!

My son and I were wiring up the trailer and couldn't make it work. It has a factory type wiring harness, five pin flat, and we were trying to splice it into a six pin round. After many fruitless tries we finally pulled the plastic side panel off to trace the wires and found a big mess of wires for the trailer lights. In this bundle are three relays and what looks like a switch and there is a hot wire that powers it all. As there is no mention of this in my Haynes wiring diagram could someone tell me how this works for trailer lights??? Is it for brakes also (no wiring at pedal)
Note: We finally just jumped this bunch of wires and went directly to the trailer. Its just a 4x4' trailer and we don't need brakes or anything but running lights, turn signals and brakes. Works just fine but I'm still curious about the wire bundle.

Never heard of a 5-pin flat trailer connector. What kind of lights does the trailer have -- are the turns separate from the brakes, or combined like most older American cars were?

Separate

I wired the trailer turns separately so that it would work better with the van. The wiring in the Jeep goes from a plug with 8 wires, thru the wire bundle with relays, etc, and ends up at another plug with 7 wires in and 5 out to the pigtail for the trailer. I suspect that this is set up to not only power lights but electric brakes also only that option wasn't put on mine. Any advice where I can get a wiring diagram for this?

You really shouldn't need a wiring diagram, just a 12 volt test light. Turn on the parking lights and find which lead is hot to ground. That's the taillights. Then left signal, then right signal. On a standard 4-pin trailer connector, the odd pin out (male on the car harness, female on the trailer) is the ground. The brake should light both signal pins. If there's a fifth pin, you need to find out whether it's a separate brake (in which case you'll need a diode isolator to keep the signals apart) or something else which you can ignore. But testing should be easy - it just requires that you see which pins are engergized when you turn on which lights.

Is this for one of the old, 80's vintahe XJs? I have wiring diagrams for the '88, which used the same adapter as the '84. Send me a PM with your postal address and I'll copy it for you.

FYI -- does your XJ have a factory trailer adapter that ends up behind the rear bumper with a flat 5-wire connector that looks like a normal flat connector on steroids? If so, there's another half to that that steps it down to a typical 4-wire with unfinished pigtails, to be spliced onto your trailer connector. It's designed for use with a simple set of trailer lights that uses the same bulbs as both brake and turn sugnal lights.

Where are these relays, drivers side rear? I'm trying to figure out what color wire circuit 20 is so I can use it for some trailer lighting relays. Theres a fuse in the box, but I don't know where it goes....

If you have them, they should be in the rear left panel -- in the cargo area.

On a 5 Wire flat, one of the leads I believe goes to the reverse light wires. Some trailers for their brakes required a wire for backing up to control trailer speed. I have only found 1 half of a 5 wire flat, and have yet to find the other. On the six wire, there is probably another wire that powers a separate lead for another battery on like a travel trailer.

Jeff