chiplee Posted April 10, 2015 Report Share Posted April 10, 2015 I'm losing my mind over some simple utility trailer lights. The lights are brand new, just wired today. The harness is a 4 flat plugged into a 2004 4Runner 7 pin through an adapter. I have no issues when I rent uhaul trailers and such, which is pretty often, but I trouble shot the truck side grounds for good measure anyway. Here's what it's doing. Everything is normal on the left trailer light. Brake, tail, turn and side marker all act completely normal. On the right, I get a very dimly blinking side marker light when I signal right, but only if the headlights are off. If the headlights are on I get nothing on the right, no brake, no tail, no blinker. Under no circumstances does the actual turn signal ever blink on the right side. Clear? Link to comment Share on other sites More sharing options...
SOTTY Posted April 11, 2015 Report Share Posted April 11, 2015 Wiring on the trailer should be brown = running lightsGreen = right turn and brake lights. Yellow = left turn and brake lights White = ground .if the Toyota has a factory tow package I doubt the fault is in the vehicle and they come with a built in convertor as these vehicals come with orange turn lenses and U.S trailers are all red , I would say the fault is in the trailer wiring Link to comment Share on other sites More sharing options...
chiplee Posted April 11, 2015 Author Report Share Posted April 11, 2015 Wiring on the trailer should be brown = running lightsGreen = right turn and brake lights. Yellow = left turn and brake lightsWhite = ground .if the Toyota has a factory tow package I doubt the fault is in the vehicle and they come with a built in convertor as these vehicals come with orange turn lenses and U.S trailers are all red , I would say the fault is in the trailer wiring Yeah, the vehicle tows all kinds of stuff with no issues. The trailer lights were a simple install, but I think it might require something the instructions didn't say. The instructions were just a matter of matching up colors and connecting. Link to comment Share on other sites More sharing options...
SOTTY Posted April 11, 2015 Report Share Posted April 11, 2015 The color codes I gave you are to U.S trailer code , my guess is a pinched wire grounding out on the trailer frame or a bad trailer ground , run a jumper ground to the trailer tongue to test Link to comment Share on other sites More sharing options...
slowquest Posted April 11, 2015 Report Share Posted April 11, 2015 LED lights or bulbs? If bulbs, double check that it has the correct bulbs, which are most likely 1157 style. I have seen very strange issues when an 1156 single element is installed. Off the wall suggestion, but very easy to check. Link to comment Share on other sites More sharing options...
wrngwae Posted April 11, 2015 Report Share Posted April 11, 2015 (edited) If its a brand new trailer,,, i would assume its a grounding issue. i bet with the fresh paint its not getting a good ground.see where they landed the ground on the trailer. i would assume your only getting partial ground thru the hitch its self. i assume its a tek screw in the frame. Edited April 11, 2015 by wrngwae Link to comment Share on other sites More sharing options...
JohnnyWadd Posted April 11, 2015 Report Share Posted April 11, 2015 i assume its a tek screw in the frame. After replacing a few truck beds I agree its a bad ground. Good way to check is do this...pull that bulb that is lighting up dimly and get a volts reading under mentioned conditions(connecting the meter prongs to the positive and negative of the female plug) . Its probably like 9-10 volts or lower. Second part of this test now connect the meter negative to a known good ground somewhere else while also keeping a connection to the positive. If that makes the volts go up to battery voltage or go up at all...then that tells you if the light circuit ground is bad. Link to comment Share on other sites More sharing options...
SOTTY Posted April 11, 2015 Report Share Posted April 11, 2015 LED lights or bulbs? If bulbs, double check that it has the correct bulbs, which are most likely 1157 style. I have seen very strange issues when an 1156 single element is installed. Off the wall suggestion, but very easy to check.yes this is a good suggestion also, ive seen this with new trailers , even seen the wrong style bulbs installed . Link to comment Share on other sites More sharing options...
SOTTY Posted April 11, 2015 Report Share Posted April 11, 2015 Tek screwing a ground into the trailer tongue after scraping the fresh paint away is the way to go and as JohnnyWadd suggested check out those bulbs . Link to comment Share on other sites More sharing options...
chiplee Posted April 11, 2015 Author Report Share Posted April 11, 2015 LED lights or bulbs? If bulbs, double check that it has the correct bulbs, which are most likely 1157 style. I have seen very strange issues when an 1156 single element is installed. Off the wall suggestion, but very easy to check. Bulbs. I swapped them side to side before I posted and nothing changed. If its a brand new trailer,,, i would assume its a grounding issue. i bet with the fresh paint its not getting a good ground.see where they landed the ground on the trailer. i would assume your only getting partial ground thru the hitch its self. i assume its a tek screw in the frame. It's an ancient trailer with brand new lights. Ground is bare metal, but the tongue could be dirty enough inside that it's not getting what it needs. I'll check that out. Link to comment Share on other sites More sharing options...
slowquest Posted April 11, 2015 Report Share Posted April 11, 2015 It shouldn't have to ground through the tongue, that's what the white wire in the plug is for. Can you tell where that white wire splices from right to left? May have a bad connection there. Link to comment Share on other sites More sharing options...
chiplee Posted April 14, 2015 Author Report Share Posted April 14, 2015 It shouldn't have to ground through the tongue, that's what the white wire in the plug is for. Can you tell where that white wire splices from right to left? May have a bad connection there. Yeah, I think that explains my confusion. Let me take a look at the way the lights are mounted to the trailer frame and I think I'll find the problem. Link to comment Share on other sites More sharing options...
83stariontravis Posted April 14, 2015 Report Share Posted April 14, 2015 Floating ground. Right signal circuit is grounding through both sets of running light filaments all in series. Lowest resistance filament is lighting. Can't ground through there when the running lights are on... explaining your specific case. Trailer lights can be a pain and a half. Intermittant Floating grounds with LED trailer lights are my favorite because the brightness is basically the same when its broke to when it's intermittantly working right. Gotta add to watch out for these(below) because I've had to track them down burried under miles of electrical tape to fix trailer light wiring at least four times. I really have no idea why lots of wiring install kits come with them and uhaul and other places that install trailer light wiring insist there is nothing wrong with them dispite my suffering and the obvious "fail" plainly seen at a glance. Seriously... I'd rather see a wire nut.http://www.kuramashop.com/ebay2011/Toppier/Cable%20Gland/KW03.JPG Link to comment Share on other sites More sharing options...
slowquest Posted April 14, 2015 Report Share Posted April 14, 2015 yeah, those things were invented by satan.... Link to comment Share on other sites More sharing options...
G54Bstore Posted April 15, 2015 Report Share Posted April 15, 2015 not sure this is your situation but if you have a clean ground where the light bulb housing bolts to the trailer that might help. Does on mine. Link to comment Share on other sites More sharing options...
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