Need Help with '88 LandCruiser Wiring Nigtmare

[jammer2340]

I have 1988 LandCruiser with a recently installed new engine. The engine was put in about 2 years ago by a Toyota dealer in Columbia SC. It has operated fine for about 2 years it burns a lot of gas but otherwise it has been great.

The trouble began when I bought a new trailer to haul my ATV's. I wired the tail lights/turn signals up to the trailer (correctly), and they worked for about 2 minutes, but I blew a fuse on the tail light circuit. I replaced the fuse twice even with the tail light harness unplugged but as soon as I turn the light switch on the fuse blows.
I tracked the wire fron the fuse box up behind the instrument panel to a junction connector and it had obviously melted. I replaced the wire but now the engine will start but runs incredibly bad or rough. Here are some of the strange symptoms that are now occuring.

If the rear wiring harness is not plugged in to the main harness the engine will not start.

If you take the signal light hot wire and tie it to the negative or ground the engine starts and idles smoothly( but it will not run at highway speed)
While the engine is running if you press the brake pedal the engine will imediately die, unless you remove the brake light bulbs.

FYI The ac compressor quit working about 2 months ago.

I have driven myself crazy trying to figure this problem out and I am afraid to take to a pro because I am sure the repair charge would be astronomical.

Your help would be deeply appreciated.

Steven

[Wellcraft19]

I would spend the money on a T repair manual and start there. Try to follow wires, make sure they are "correctly" routed and properly terminated..

What likely happened is that you overloaded the tail light circuit (in the LC) by adding the load of the trailer lights. You will need to run a dedicated power wire to the rear of the LC for the trailer, and install a "trailer converter" that only contains relays that are powered off the LC's light circuits. Then all the load for the trailer ligths will be on your newly installed feeder, and none on the LC's circuits (apart for what is needed for the relays).

These converters are a bit pricier, but in a case like this, it'd paid for itself in "about 2 minutes".

Far too many people are running too many trailer lights directly off the car's circuits. When a problem occur, more than a fuse migth blow and you have bough yourself a real nightmare.

Can you provide any simple drawings to the list? Sort of hard to help out with a "shallow" description.

OK, not much help, but you will need a manual, or another LC of same vintage where you can "compare and contrast".

Best of luck though.