spiderwebfx Posted February 23, 2013 Share Posted February 23, 2013 Hey all, I've got a problem with one of our work trailers and I can't for the life of me figure out the problem. It is a lighting issue, and everything works fine until the brakes are applied. Left indicator does left, right indicator does right, taillights work. When the brakes are applied, the light up every bulb! If they're applied when the right indicator is on, the right indicator stops and left side blinks and vice versa. The indicators also make the taillight bulbs dim when on. I checked the wires with a volt meter and I think the problem is the ute not the trailer. When the brakes are applied, I get a voltage reading between the brake wire and all other wires. Everything else is fine. Makes me think that the wires are crossing over somewhere but I don't know where. All the lights on the ute work fine. Has anyone got any thoughts? Quote Link to comment Share on other sites More sharing options...
My name is Russell Posted February 23, 2013 Share Posted February 23, 2013 Checked if it does the same hooked up to another car? Quote Link to comment Share on other sites More sharing options...
spiderwebfx Posted February 23, 2013 Author Share Posted February 23, 2013 No, don't have another car to hook it up to atm. I can try again on Monday, just wanted it sorted as I need to use it tonight. Quote Link to comment Share on other sites More sharing options...
AllTorque Posted February 23, 2013 Share Posted February 23, 2013 Sounds like an earth fault.check for earth from the stop bulbs Quote Link to comment Share on other sites More sharing options...
spiderwebfx Posted February 23, 2013 Author Share Posted February 23, 2013 Sounds like an earth fault.check for earth from the stop bulbs On the trailer? Only reason I ask is because when I'm testing the circuits without the trailer plugged in, I get current from the brake light to every other wire. Quote Link to comment Share on other sites More sharing options...
evil_si Posted February 23, 2013 Share Posted February 23, 2013 Brake light powerwire shorted to chassis, Quote Link to comment Share on other sites More sharing options...
spiderwebfx Posted February 23, 2013 Author Share Posted February 23, 2013 Brake light powerwire shorted to chassis, Would this 'cause the brakes on the ute to work funny? I've checked the brake wires back to where it joins the main vehicle loom and there is no problems with it there. Trying to decide the next place to look. I.e. rear brake lights, just follow the loom or? Quote Link to comment Share on other sites More sharing options...
Bling Posted February 23, 2013 Share Posted February 23, 2013 Inside the plug? Short could be inside, unless it's not a DIY plug. Quote Link to comment Share on other sites More sharing options...
spiderwebfx Posted February 23, 2013 Author Share Posted February 23, 2013 Definitely not the plug. That was the first thing I checked. Quote Link to comment Share on other sites More sharing options...
Bling Posted February 23, 2013 Share Posted February 23, 2013 So the wiring at the plug on the ute is giving the problem with nothing connected? I guess next is the pull the lights and check them to be fine / the wiring loom to the lights also. Quote Link to comment Share on other sites More sharing options...
be4ver Posted February 23, 2013 Share Posted February 23, 2013 definately an earth problem, all your lights will be earthing through the stop bulb filaments then when the brake bulbs are powered up everything will go funny trying to find a path to earth. id say either there is no earth in your plug on the vehicle or its not getting through the plug or the wires broken somewhere. earth is the middle pin if its a rectangle plug Quote Link to comment Share on other sites More sharing options...
spiderwebfx Posted February 23, 2013 Author Share Posted February 23, 2013 So the wiring at the plug on the ute is giving the problem with nothing connected? I guess next is the pull the lights and check them to be fine / the wiring loom to the lights also. I'm pretty sure it is the ute. Like I said, with the trailer not plugged in. I've tested the brake wire on the plug with every other wire (including the ground) and it has current. I pulled the rear lights and inspected them and there appears to be nothing wrong with them or the wires. definately an earth problem, all your lights will be earthing through the stop bulb filaments then when the brake bulbs are powered up everything will go funny trying to find a path to earth. id say either there is no earth in your plug on the vehicle or its not getting through the plug or the wires broken somewhere. earth is the middle pin if its a rectangle plug Plug definitely has the earth. I've checked that, and replaced the earth wire from the plug to where it joins the chassis loom. Where I'm at now is actually pulling the chassis loom apart and inspecting the brake wires in there. Quote Link to comment Share on other sites More sharing options...
spiderwebfx Posted February 23, 2013 Author Share Posted February 23, 2013 Just another thought I had, is it possible an incorrect bulb in the ute may cause an issue with trailer wiring? I haven't checked them at all, but just trying to eliminate the easiest options first. Quote Link to comment Share on other sites More sharing options...
WarrenW Posted February 23, 2013 Share Posted February 23, 2013 Clean up the pins on the plug and give that a go. Quote Link to comment Share on other sites More sharing options...
spiderwebfx Posted February 23, 2013 Author Share Posted February 23, 2013 Clean up the pins on the plug and give that a go. Have done this already. Wire brushed them and saturated them with contact cleaner Quote Link to comment Share on other sites More sharing options...
be4ver Posted February 23, 2013 Share Posted February 23, 2013 if ya lights on the ute are going properly then the trailer plug should be right also unless its wired up wrong. also have ya made sure the pins on the trailers plug arent squashed together? doesn't take much some times. stick a knife blade between them and spread them apart a little. failing all that pull the lens off one of your trailer lights, get a piece of wire and touch one end to the earth bit in the light and the other end to some metal of the trailer. if the problem goes away then youll just need to sus out where its losing the earth. do the same in the trailer plug even Quote Link to comment Share on other sites More sharing options...
sr1600 Posted February 23, 2013 Share Posted February 23, 2013 Pull the bulbs out of the lights and then check the wires against the chassis with them out will tell you if the wire has rubbed through somewhere so you can eliminate that. Quote Link to comment Share on other sites More sharing options...
spiderwebfx Posted March 1, 2013 Author Share Posted March 1, 2013 Brief update. The trailer is definitely not at fault. Hooked it up to our other work ute and they work fine. Still can't find the problem with it so it's going to an electrician next week. Quote Link to comment Share on other sites More sharing options...
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