Buy kit at Wal-Mart, auto parts, or U-haul comes with instructions
The trailer has a dead short in that right side brake light circuit.
Somewhere rear brake light area.
how would remove brake light switch and replace on an 88 gmc
short circuit on trailer light wiring
Your trailer tailights are dual-filament, with one being the running lights and the other the brake lights. You need a separate power source from your towing vehicle's brake lights to power them. The easiest way to do this is go to U-Haul and but a set of their trailer towing taillight bulbs for your towing vehicle. The bulbs replace your standard tail/brake light bulbs, and they have two wires coming out of the base of the bulb. One of the wires connects to your trailer's running lights, and the other one connects to your trailer's brake light circuit. I'm trusting that when you re-wired your trailer, you ran two wires from the taillight socket, one for the running lights and one for the brake lights. In some trailers, the brake light circuit also doubles as your turn signals. Good Luck.
Vehicle side, Brown, running lights Yellow, left signal/brake light Green, right signal/brake light Black, ground Trailer side, white is ground
Sounds like a weak ground connection somewhere on the trailer or tow vehicle.
Start with: Check fuses, brake light switch (at brake pedal), check for trailer harness problems, check bulbs.
If you have a 1998 or newer it could be a fuse in the power distribution center under the hood. The whole trailer light system is fused through there.
1 faulty brake light switch, 2 faulty wiring from switch to taillights. Possible short on trailer jack (if fitted).
#1 reason is always bad GROUND. Now you really weren't all that specific about which plug. Trailer plug on the vehicle or actually on the trailer? If it's the plug on the vehicle, I would strongly suspect bad ground or installation was backwards. If on the trailer, merely backwards installation. In any case, get better trailer light performance by running separate ground wires to each individual light socket on the trailer and connect them to the ground wire at the plug so they will be grounded to the vehicle at time of connection. I do this with all of my trailer lighting and never have issues.
They are lights that go on your trailer to show your turn signal and brake lights. Reese Hitches has all of the top brands if you're in the market for some: http://www.reesehitches.com/product_categories/trailer_lights