OK guys and gals, I bought a 6x10 enclosed trailer and the plug was a little rough so I got it home yesterday (couldn't plug the lights in to check them cause the plug was chewed up) so I got the 2 miles home without. Today I wired a new pigtail on and all was good or so I thought. Of course I get no lights working. My truck has a trailer connector plug factory wired, I tested it with the multi meter and it works. I next pugged the trailer in to it and jammed the test probes into the harness past my splice, and we are good up to that point. Now it gets weird... Pulled the trailer light bulbs and put the multimeter up to the socket in both sides. Showed voltage fluctuation I time with the turn signal flasher on the truck, so should be good.. Tested the bulbs with the Ohmmeter and all the bulbs were fine. Plugged everything back in and still no lights anywhere on the trailer. If it were a bad ground somewhere wouldn't the sockets not test correctly? Anyone got any ideas what the heck is going on here?
Did you have the trailer hitched up? Either that, or connect a ground wire between the trailer and the tow vehicle.
I'm a little leery any time I hear hack this, jam that, stuff the other. T/S can back-feed through the tail lamp circuit under certain circumstances, so it can still be a crap ground.
A far as turn signals back feeding as you mentioned, l understand that is what a trailer converter box is for, some situations if you activate one TS it will make both on the trailer flash and the converter box has transistors in it to correct this. But my setup is not doing that, it either works or it doesn't. Yep I think it is a bad ground somewhere, I hooked up the hitch and now the lights work correctly, but that should not make a difference, so far as I know. Also the multimeter could show voltage but when there is a load on the circuit with the resistance of the bulbs, it could not be a good enough ground. The problem is this thing has a bunch of marker lights and stuff wired in parallel so how to find the problem is a pain, and I'm not that patient. Arghhh
What kind of truck? just a warning Dodge doesn't use fuses for the turn signals and if you trip BCM over current dealer has to flash memory (don't ask how I know) and they weren't sure how many times they could reset it at $75.00 a pop and $750.00 for the module if they cant flash it. I'm assuming it is a standard 4 wire plug on trailer and heavy duty flasher (if truck has flasher) leave trailer off the ball run a jumper wire frame to frame I would take a jumper wire from battery or bat terminal on 7 pin plug. hook battery wire to yeLLow wire Left turn signals and make sure they work repeat for the gReen wire Right turn signals and make sure they work repeat for the brown wire clearance lights and make sure they work if they are ok wit the above test then hook truck to trailer and work on the plug problem Most problems on trailers are as you have drug plug or corroded connections. I use gell filled scotch locks #314 connectors on the wiring to prevent corrosion. http://solutions.3m.com/wps/portal/...ECIE20S4K7000000_nid=GSV0X23YGMbeVB2NDGZBTHgl
Yes it is a 2010 Ram. Now you got me thinking, because I have towed a few different trailers with it and a couple horse trailers worked fine, but I hooked up a boat trailer to it last year and the lights never worked, but I hooked it up to my Dad's old Ranger and the lights worked fine. The are some very strange compatibility issues and I suspect now that if the truck's computer doesn't like it it simply won't play nice with it.
Based on what I am reading, you don't have the ground hooked up through the connector, THE BALL IS NOT THE GROUND CONNECTION. Here's a good link to trailer wiring diagrams http://www.etrailer.com/faq-wiring.aspx
I have an 06 2500 mega cab and the trailer turn signals don't work if the truck isn't running (dodge brainstorm just like doing away with the fuses). The dealer didn't even know that when I had them "fix" them it took 3 times 1st they said it was a corroded connector on the bumper and replaced that took it home and tried it still broke 2nd they hacked the harnase apart trying to fix it said they got it and I took it home again still didnt work the 3rd fix I found the schematics on line and told them what wires to test on the BCM ad they then they found the BCM tripped. I not so politely explained to them that I was an electrician and brought it to them because they were suppose to be capable of fixing it and it was pretty bad that a customer had to tell them what to look for. I didn't have to pay for the last 2 visits since then I installed fuse holders in the harness with 5 a fuses BCM is set to 7.5 so the forums say. I even offered to come in and run a class on how to trouble shoot wiring problems their reply was their tech were Chrysler trained and I said they needed more. I'v never been back to the dealer after that!!!! I agree with the ground problem. but i think you have 2 problems going on.
I had an issue with my boat trailer that I simply couldn't solve until I replaced the incandescent rear stop/turn lights with a $40 LED set from HF. All-weather in-line connected them to the existing trailer wiring. Good to go.
Sounds like a ground issue. Once again... the ball and hitch are not a acceptable ground. Check all grounds.
I ended up deciding that it was a bad ground on the trailer side, but never really figured out where.. I ran a jumper from the white wire in the harness over to the trailer frame and now all the lights work. Thanks for all the suggestions, strange symptoms but a simple fix.
This is typical of trailer wiring. The chassis ground connection corrodes because it is exposed to the weather. Last one I did I got the frame area cleaned up with a scotchbrite disc, then used a star washer between the wire lug and the frame for good contact. I then completely potted the connection with non-acidic RTV caulk. 15 years later, it's still going strong.
Um.. Yup. Because that is the problem 99% of the time. Or, people use Scotch lock connectors and the copper turns to black dust in all the wires... Good grounds are mega important. Then solder and heat shrink all connections.
I have been fixing bad ground by welding stainless bolts to the trailer and using stainless lock nuts for all the ground points. So far that has fixed all my ground issues on all the trailers I have done it to. Next biggest issue, chaffed wires.
That's been one holdup on my long-running trailer light project. The factory conduit isn't big enough to accommodate jacketed 7-conductor cable, and I'm loathe to punch two 5/8" holes in all my crossmembers to make two 1/2" conduit runs to the back. Clamping conduit beneath the crossmembers seems like a good way to tear out all the wiring, and there isn't a good way to run it up under the side rails, either. If I had a torch and welder, I could remove the factory conduit and weld in larger replacement, but then the trailer would be down until I got finished.
Yea, the problem was as you were alluding to, on an enclosed trailer there is just not much of a way to get to the wiring to even inspect it for corrosion and loose connections because I'm pretty sure they built the body around the wiring harness. The trailer wasn't in bad shape when I bought it, actually only a couple years old but the previous owner (original purchaser) has used it for his carpentry business and it looks like it took lots of rides on salty roads and was never washed. Lived a hard life for a few years. Next up, hubs and bearings, which are in my parts washer as we speak!
