Jim McC Posted July 13, 2011 Posted July 13, 2011 I just noticed tonight that when I hit the brakes, my trailer's left turn signal activates. Everything else works normally. What could be causing this? Thanks. Quote
Super User J Francho Posted July 13, 2011 Super User Posted July 13, 2011 Don't know, but it's a simple rewire job. Just use the old wires to snake the new ones through. I just wired mine - solder and heat shrink all the way, with new LED tail lights. Took me about three hours, and I'm a rookie. Quote
Super User Nitrofreak Posted July 13, 2011 Super User Posted July 13, 2011 Don't know, but it's a simple rewire job. Just use the old wires to snake the new ones through. I just wired mine - solder and heat shrink all the way, with new LED tail lights. Took me about three hours, and I'm a rookie. I have to agree with J here, It sounds like a ground problem but in my area when you start having issues you keep having issues, Go to Wal-Mart or thier web site you can get the whole kit for 30 bucks. Just be sure to check the vehicles plug before you do to be sure its not in that part of the circut. Quote
Super User J Francho Posted July 13, 2011 Super User Posted July 13, 2011 If the lights still work, the wiring harness is less than $10 for a 25' 4-pin kit. No point in replacing something that works. Use this, or whatever hook up you have, with the indicator lights to tell you if your hook up is working properly: Or this: Quote
Super User Jig Man Posted July 13, 2011 Super User Posted July 13, 2011 I own 3 trailers and most of the problems I have had are bare wire or bad grounds. The first thing I'd do is check all the connections and sharp bends. It could be a simple ground problem and or a frayed wire. If you can isolate the problem it may be a fifty-cent fix instead of a $20 and 3 hour fix. Quote
Super User J Francho Posted July 13, 2011 Super User Posted July 13, 2011 You never know what's hiding in those rails, LOL. I was shocked. What a mess. Glad I started fresh. Quote
Ann-Marie Posted July 13, 2011 Posted July 13, 2011 THE ULTIMATE SOLUTION TO TRAILER WIRING PROBLEMS. I mounted the license plate, stop lisghts, clearance lights turn lights etc, all on a 2X4 and made a clamp that would attach it to the trailer or the stern of the boat. A flexible cord plugs into the truck. No wiring on the trailer to give problems. (May not be quite legal to include the license plate but no one ever gave me any trouble.) You hang it on the trailer or boat when going to move, take it off, roll up the cable and put it back in the truck when you arrive. No need for waterproof fixtures, no burned out bulbs from the water, no rusty connections. Quote
Triton21 Posted July 13, 2011 Posted July 13, 2011 I just rewired my boat trailer and car hauler. I ran the wires inside a cheap water hose cut in the lengths needed. No chaffing the wires on the inside of the rails on boat trailer or through the holes on the frame of the car hauler. Kelley Quote
Jim McC Posted July 14, 2011 Author Posted July 14, 2011 I just rewired my boat trailer and car hauler. I ran the wires inside a cheap water hose cut in the lengths needed. No chaffing the wires on the inside of the rails on boat trailer or through the holes on the frame of the car hauler. Kelley That's a great idea. I'll have to see if I have room to run a hose or something similiar(if I re-wire it). A local U-haul dealer checked my van's wiring harness today, and everything worked normally. He said it's probably a bad ground or a bad wiring plug on trailer. So at least now I know it's the trailer itself. How do I check to see if the trailer wiring plug is bad? How do I check for a bad ground on trailer? Thanks. Quote
Team_Dougherty Posted July 14, 2011 Posted July 14, 2011 I just noticed tonight that when I hit the brakes, my trailer's left turn signal activates. Everything else works normally. What could be causing this? Thanks. Does your trailer have separate brake and turn signal bulbs? Most trailer lights use an 1157 bulb. The brake light and turn signal use the same element in the bulb. Maybe your right brake light is burned out. Does the left light blink when you step on the brake? Quote
Jim McC Posted July 15, 2011 Author Posted July 15, 2011 Does your trailer have separate brake and turn signal bulbs? Most trailer lights use an 1157 bulb. The brake light and turn signal use the same element in the bulb. Maybe your right brake light is burned out. Does the left light blink when you step on the brake? I've got LED trailer lights, new last season. Yes, the left turn signal activates when I hit the brakes. Quote
Team_Dougherty Posted July 15, 2011 Posted July 15, 2011 I've got LED trailer lights, new last season. Yes, the left turn signal activates when I hit the brakes. Interesting. The blinking is controlled by the flasher in the tow vehicle. I agree with the others. Check the trailer wiring. The LEDs need a really good ground to work properly. Quote
Jim McC Posted July 15, 2011 Author Posted July 15, 2011 Interesting. The blinking is controlled by the flasher in the tow vehicle. I agree with the others. Check the trailer wiring. The LEDs need a really good ground to work properly. OK, but what do I check specifically? How do I know if a ground is bad? Each LED taillight is grounded with a screw, and those look clean. The trailer harness is grounded to the frame, but the screw is rusty. Quote
Team_Dougherty Posted July 16, 2011 Posted July 16, 2011 OK, but what do I check specifically? How do I know if a ground is bad? Each LED taillight is grounded with a screw, and those look clean. The trailer harness is grounded to the frame, but the screw is rusty. There should be a white wire going from the trailer to the tow vehicle. you should not rely on the ball and the coupler to provide ground. to check run a wire from each tail light ground to a ground on the tow vehicle. Quote
Jim McC Posted July 16, 2011 Author Posted July 16, 2011 There should be a white wire going from the trailer to the tow vehicle. you should not rely on the ball and the coupler to provide ground. to check run a wire from each tail light ground to a ground on the tow vehicle. I've never had a white wire going from the trailer to the tow vehicle. How would that even hook up? Quote
Jim McC Posted July 17, 2011 Author Posted July 17, 2011 Update: Today I re-did my 2 grounds from the taillights to the trailer frame. I also re-did the ground from the trailer harness plug to the trailer frame. The bad news is it's still doing the same thing(When I step on the brake, the left turn signal flashes on the trailer). Everything else works normally(The left and right turn signals and the hazards). When I put on the hazards though, the 2 taillights are slightly out of sync by a split second. Does this hint toward anything? Tomorrow I'm going to replace the trailer harness plug and see what happens. Thanks for any help. Quote
Team_Dougherty Posted July 17, 2011 Posted July 17, 2011 I've never had a white wire going from the trailer to the tow vehicle. How would that even hook up? Quote
Jim McC Posted July 17, 2011 Author Posted July 17, 2011 I've got the white wire from the plug grounded to the trailer. Is that what you mean? Quote
Team_Dougherty Posted July 17, 2011 Posted July 17, 2011 I've got the white wire from the plug grounded to the trailer. Is that what you mean? you also need a the white wire grounded to your tow vehicle. You can not rely on the ball and coupler alone. Quote
Jim McC Posted July 18, 2011 Author Posted July 18, 2011 you also need a the white wire grounded to your tow vehicle. You can not rely on the ball and coupler alone. Do you mean the ground wire that should have been installed when they installed my hitch and wiring on my van? Quote
Super User J Francho Posted July 18, 2011 Super User Posted July 18, 2011 Yes. The one "oddball" opposite connection is the ground. On the vehicle side, the white line should be grounded somewhere on the van. On the trailer side, it's grounded on the trailer itself. Quote
Jim McC Posted July 18, 2011 Author Posted July 18, 2011 Yes. The one "oddball" opposite connection is the ground. On the vehicle side, the white line should be grounded somewhere on the van. On the trailer side, it's grounded on the trailer itself. Thanks. Now I have to find the ground on the van and see how it looks. Any tips on how to find it? Quote
Super User J Francho Posted July 18, 2011 Super User Posted July 18, 2011 I'm sure they installed it correctly. I still think you should just rewire the thing. It was WAYYY easier than I imagined. Quote
Team_Dougherty Posted July 18, 2011 Posted July 18, 2011 Thanks. Now I have to find the ground on the van and see how it looks. Any tips on how to find it? follow the white wire from the plug to the ground screw on the van. Quote
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