Trailer wiring ???
 

Bought a used enclosed trailer---all the lights work HOWEVER when you turn on the flashers or turn signals not only do the taillights work on the trailer although not real brite BUT the clearance lights on the trailer all flash and the Stop lite on the cab flashes too---BOTH turn lites on the truck flash but depending whether you are signaling left or right whichever way you signal that lite will be brighter than the other taillite but both are flashing---Disconnect the trailer and the truck is OK--put a new 7 prong plug on the trailer cuz the old one was a little scuzzy that did not help--- The guy I bought the trailler from had just installed ALL NEW Led clearance lites and 2 NEW regular (not LED)stop/turn lites---Anybody got any ideas??? I think I have a pinched wire some where but do not want to tear the whole interior out to find it---He also put new wood on the ramp door but I have no idea if he rewired it while he had that open- Suggestions gratefully accepted--Thanx Comp 387

Re: Trailer wiring ???
 

I had a problem similar to that. They had one of the brake lights wired to the running lights.
When you put on the lights the brakes locked up.
Trailer wiring on trailers built up north can be a real problem to get to, because they are all enclosed.

Re: Trailer wiring ???
 

Add a ground wire from the truck frame to the trailer frame and the trailer frame to rear door frame. We have several older haulmarks that had the same problem and that cured it.

Bill

Re: Trailer wiring ???
 

OK guys Thanx will look into both ideas---anybody else got any more ideas??? Thanx FED387

Re: Trailer wiring ???
 

Sounds to me like you could have a bad ground and some wires crossed up in your plug. Had some of the same problems on my Goldrush this summer and spent 2 days trying to figure it out. Are your trailer wires color coded? If I remember corectly the yellow is left turn, the green is right turn the black is taillights, the white is ground the brown is running lights, the red is to charge the trailer battery and the blue is the trailer lbrakes. The ground wire (white) has to go into the center post of the plug. Hope this helps some.

Re: Trailer wiring ???
 

Wayne just double checked the wiring on the PLUG---the colored wires are where they are supposed to be---the center wire position on the trailer plug has no wire attached to it --never did days its for backup lites-no wire in the harness is available to attach to it---I do not understand how you run a ground wire from the truck to the trailer when I think going thru the hitch ball would work but if that is not the case how do you ground the trailer to the truck or the trailer door to the trailer frame???( hinges on the trailer door metal on metal not a good enough ground???)---I'm game talk to me this is exasperating spent all day Sun futzing with this bout ready to completely rewire the frigging trailer get it over with BUT I dont wanna do that hafta pull the ceiling down etc.--- Keep those ideas coming ---Comp 387

Re: Trailer wiring ???
 

Just try temporarily hooking a jumper cable from the truck frame to the trailer frame, to see if grounding is the issue.

Re: Trailer wiring ???
 

I agree... sounds like a ground wire problem for sure. The LEDS
are not as fussy as conventional bulbs. When the ground is bad my trailer do a lot of backfeeding and funny stuff.:)

Re: Trailer wiring ???
 

It's more than likely a grounding issue from truck to trailer. This has happened to me before, but as soon as i started driving the ball and hitch made a good ground and it worked fine. Good luck!

Shawn

Re: Trailer wiring ???
 

Make sure that your brake light bulbs are indexed properly. I have seen where it is possible to install the bulbs 180 degrees out and cause this condition.

Re: Trailer wiring ???
 

We had a problem similar to what you have. Check the new light wiring, he may have pinched a wire.

Re: Trailer wiring ???
 

Seems odd that the park lites come on the trailer light when you use turn signals. Does your truck have seperate stop and turn bulbs? If so I've you require a "module" to operate the trailer lites correctly if the stop and turn on the trailer use the same bulb.If in fact the Park lites come on with the turn or flashers, you may have a simple feedback issue thru one of the new lites. What I would do is use a jump box or battery and go right to the trailer plug (no truck) and test all my lites. This will tell you if the trailer wiring is sound. Joe Most any "modern" trailer has a dedicated ground thru the plug so you can check the ground during your "battery" test, I used to remember the positions by heart however I'm sure the 3 oclock pos. is RH stop and turn the 9 oclock pos. is LH stop and turn. this is looking at the truck plug from behind.Keep us posted

Re: Trailer wiring ???
 

Joe--same bulb for stop & turn & tail lites( 1157 bulb in it) bulb is in correctly too----the clearance lites (all of em) flash when you turn on either the turn signals or emergency flashers---the stop/tail on the trailer works but they are dim--the stop lite on the roof of the cab(2000 Ford Super Duty) flashes too---the clearance lites work great UNTIL you turn the turn signals on have not tried it with the brake pedal did not think of that---seems to me that there is a ground wire thru the plug ---maybe climb under the trailer see where it ends up and if the ground there is bad to clean it off or drill a new hole---well I'll look at it tonite--thanx for the ideas will try a seberate battery test each circuit see if I have a bad wire someplace--thanx Comp387

Re: Trailer wiring ???
 

OK then you either have a bad ground or you're "feeding" back thru one of your rear lamps or sockets. Remove both rear TS stop lamp bulbs and try again, if it seems OK tryreinstalling1 bulb at a time to try and narrow it down to a particular socket. By removing both rear bulbs you're taking away the "feedback" path. Make sure the socket ground wires at the rear are connected as this could be your "feedback" path.Joe Your rear socket should have 3 wires 1 for tail 1 for TS stop 1 for ground

Re: Trailer wiring ???
 

Joe, the trailer should ground the turn/stop lamp...........

Re: Trailer wiring ???
 

Do you have grease on your hitch ball. If you do you will need to ground the trailer. Then in trailer plug facing it about 5:00 is your ground.. Run wire from plug back to a good ground on trailer. Truck ground is at 7:00 make sure you have a good ground..



For Infro only

7 Way Plug Typical trailer wiring / position Knot on top at truck
Performance Trailer
Green is running lites / 11:00
Brown is right turn /3:00
Blue is brakes / 5:00
White is ground / 7:00
Red is left turn / 9:00
Black is a charging lite / 1:00
Yellow is back up / center

Re: Trailer wiring ???
 

You can't depend on the hitch being a good ground. For years when we would start traveling the lights would not come on at first and as we would travel they would blink or get dim and when we would make a turn they would come back on and then go off or get dim until the rust would wear off of the ball and even then they would act up at times. If you have grease on the ball it will also cause a bad ground. What I found was the ground wire on the plug had come disconnected. On your plugs there should be a center post where the white wire slides into it and then there is a small screw that holds in in place. I know what you are going through, frustration isn't the word, I got so I couldn't thing while doing this. On a Goldrush they have a panel where all the wires connect and they are marked (brakes, running lights,etc) and the wires are color coded. Could the plug on the truck be wired incorrectly? Once you are sure you have a good ground take the truck plug apart, turn the truck lights on and see which turminal has 12 volts. Take a small jumper wire from that terminal and touch each terminal on the trailer plug until your trailer lights light. See if the wire color on that terminal matches the wire color at your back door. The wires probably run down the ceiling to the back corner and down. You should see wires from the trailer going into the door. They might be green, yellow and I think black. You should be able to pull the whole light assembly out of the door to be able to see what color wires are there. Hope this helps and good luck!!!!!!

Re: Trailer wiring ???
 

Bob ,yes I know however if the ground for the pigtail or socket is not connected it may be trying to find another path to ground.depending on the bulb and socket design it may be grounding back thru the filament in the bulb hence backfeeding another circiut since the tail and turn lamps are on completely different circuits.I've even seen some people put a single contact I believe 1156 bulbs in dual contact sockets and cause the same sort of issue. Joe Oh and one other thing I see alot of ,when guys wire plugs a single stray wire touching the adjacent terminal can cause this issue. Sorry don't mean to confuse you just hard to diagnose not being there.I also neglected to ask, do the trailer brakes work? If so I doubt you have a grounding issue as thet use the most power of anything on the trailer.

Re: Trailer wiring ???
 

In about 1973,I worked for a gas station that had U-Haul rental trailers and trucks.You never saw junk until you saw their stuff. People used to rent a trailer, a clamp on bumper hitch, and wonder why the lights misbehaved. That was when bumpers had those big gas shocks suspending them, and continuity of ground wasn't too good to depend on. An auto electrician good enough to quickly diagnose and repair these issues that trailer lights can cause was enough of a rocket scientist that he didn't need to work there. Feed back through defective bulbs, sockets, and grounds would turn a saint into a drinking man. The suggestion to make sure all bulbs are correct for the socket is a good place to start. It might be necessary to remove all bulbs in the trailer, then re-install them one at a time until the glitch reappears. Good luck- it's probably something simple.

Re: Trailer wiring ???
 

Ground the thing.

Re: Trailer wiring ???
 

We added a #10 wire with solderless connectors. Eyes bolted or selfapping screwed to each frame, with spade/ female connector between them. The short pigtail stays with the truck and we taped the extra wire from the trailer to the plug lead. then a short wire between the trailer frame and door frame and all off those same issues went away. the whole thing took ten minutes.

Re: Trailer wiring ???
 

As I stated earlier all of the trailer wiring issues can be diagnosed using a battery and some jump leads. Leaving the truck out of the equation eliminates confusion, if everything checks out at the trailer(which I'm fairly sure it will not) it would be an issue of incorrect wiring positions. I've found that breaking problems down to sub categories helps make the diagnosis easier. Start with JUST the trailer it avoids confusion. Good luck and let us know the outcome. Joe

Re: Trailer wiring ???
 

What he said....

Re: Trailer wiring ???
 

We do these everyday at the shop so if you haven't solved it yet......if your truck has factory trailer wiring you should be fine there.....if the trailer still has the industry standard color coded cable (wiring) the trailer plug on the trailer gets wired like this with a 7 blade connector....to make it easy ignore the colors printed on the plug and socket and go only by the blade numbers (very small).....

#1....white...10ga wire...ground
#2....blue....12ga wire....trailer brakes
#3....brown....14ga wire.....tail lights,license plate light,marker lights
#4....orange or red....10ga wire....battery charge wire
#5....yellow......14ga wire.......left stop,turn signal
#6....green.....14ga wire.......right stop,turn signal.....
#7.....aux....can be used for whatever,leave empty

if everything is cool from there you said that the previous owner replaced the tail lights (stop/turns)......after double checking everything so far and the ground connection on the trailer frame here is what I would check next.....

The stop/turn light pigtails are 3 wires...one white(ground wire) one black(marker light wire) and one red(stop/turn).....if the previous owner replaced this pigtail it sounds like this is where the problem may be....it sounds like he has the marker light of the pigtail connected to the stop/turn on the trailer wiring,this explains why your trailer tailights blink dim and the marker lights blink also when you put on your turn signals....this would also give a feed back through the trailer plug into the truck causing it to do some strange things too.....


let us know what you find out.....

D L Rambo

Re: Trailer wiring ???
 

You can also use a good dielectric grease on the ball, after you clean off both surfaces. it will help with the round connection. Rust to rust doesnt make for good solid ground connections.

Re: Trailer wiring ???
 

NO trailer should be grounded thru the ball or hitch! Joe

Re: Trailer wiring ???
 

I recently fought this with my trailer. Found one of the contact (solder)buttons from the lamp sheared off & laying across both socket contacts, thereby shorting tail & running lights to the brake/ turn filament. Mine were also brand new replacement lights (made in China, of course). Vaseline on the lamp base helps to twist past the Mickey Mouse contacts on Mickey Mouse lights! :mad: Will also help fight corrosion.

Re: Trailer wiring ???
 

Comp 387, did ya ever get the trailer lights working the way they should ?
If so what was the problem............

Re: Trailer wiring ???
 

OK guys----These were the problem(s) I have found so far & the corrections I made

1---ground wire anchor/crimp connector on trailer rotted/rusted/bad connection----corrected also made a plug in connector directly to the truck frame from trailer frame

2---Pinched wire harness at rear between fold down trailer door and box--rerouted/rewired from box to door

3---Bad/poor crimp connectors in taillight harness inside of ramp door( had to remove flooring on ramp door)---rewired & replaced both taillight assemblies

4---pigtail connecter going from trailer to receptacle on truck wired incorrectly( wires were in the wrong position)-----put them in the correct position on the pigtail

Gonna take it for a drive see if all works as it should--see if anything craps out and hopefully everything works as it should

I wanna thank everybody that responded and offered their suggestions---I am/was at my wits end trying to figure this out---Did not think that there would be so many problems musta spent 8-10 hours trying to fix this !!!!! But now that it all works so I'm gonna sell this trailer to some sucka!!!!!! No really I stole this for next to nothing ( I see why the guy sold it so cheap) Thanx again Comp 387