So I just bought a brand new dual axle utility trailer. My cousin had to tow it home from the dealer because something is wrong with the wiring on my truck. Everything worked fine when my cousin towed it with his 05 Silverado so I doubt something is wrong with the trailer itself. I have an 03 Silverado with the factory tow package. The brake lights and turn signals work fine on the trailer during the day with my lights off. However, when I have my headlights on and I use either blinker, everything on the trailer just flashes including all the clearance lights. Also, when I press my brakes, the taillamps go out. Anybody have any idea as to what might be causing this? I'll try to get a video up when I can.
Trailer Wiring Issue
- Thread starter VortecZ71
- Start date
- Views: 12701
KB9UDE
Platinum Member
- Joined
- Apr 23, 2006
- Messages
- 969
- Location
- North of Tower Hill, IL
- Tractor
- John Deere 4066r John Deere 2025r
Sounds like a bad Ground connection to me.
brokenknee
Platinum Member
I agree, that would be the first thing I would check.
outinthetalgrass
Silver Member
I second that... bad ground between truck and trailer.. when lights are off tail light and turn signals using light circuit for ground.
Dmace
Elite Member
I agree with a bad ground being the problem. Try taking a jumper wire (wire with two alligator clips on it) and connecting it to bare metal on the trailer and bare metal on the truck and see if it helps.
jeffsw6
Gold Member
I think your truck's connector is wired differently and what should be the ground is really connected to the trailer relay for your headlights, which is probably grounded except when you turn the lights on?
I think this is the most common wiring scheme: http://www.cumminsforum.com/forum/a...-pin-connector-wire-colors-7waytrailerend.jpg Keep in mind this will look right/left swapped depending on which way you are looking at the connector, e.g. the trailer's socket or the vehicle's plug.
I would get a friend and a VOM or 12V lamp and loose wire, and test what is really coming from the connector on your truck. If it's not right just change it. If you don't have a soldering iron and heat shrink kit (or are like me and can't hold your hand steady enough to solder) then get someone to correct it for you.
It is possible it could be a more complicated problem but I seriously doubt it. I have seen other 7-wire schemes and the auto parts store I go to even has some adapters on the shelf to go from one kind of 7-wire to a different kind.
I think this is the most common wiring scheme: http://www.cumminsforum.com/forum/a...-pin-connector-wire-colors-7waytrailerend.jpg Keep in mind this will look right/left swapped depending on which way you are looking at the connector, e.g. the trailer's socket or the vehicle's plug.
I would get a friend and a VOM or 12V lamp and loose wire, and test what is really coming from the connector on your truck. If it's not right just change it. If you don't have a soldering iron and heat shrink kit (or are like me and can't hold your hand steady enough to solder) then get someone to correct it for you.
It is possible it could be a more complicated problem but I seriously doubt it. I have seen other 7-wire schemes and the auto parts store I go to even has some adapters on the shelf to go from one kind of 7-wire to a different kind.
grsthegreat
Super Star Member
i have never seen a factory wired tow package that isnt wired correctly, cause there usually plug and play systems. I DO know that a bad ground will play havoc with trailer wiring. Ive had it myself many times. I agree on testing it with a separate wire connecting a good ground sorce to the trailer and see what happens.
On the wifes 94 dodge ram truck, i found the ground wire had rotted away where it bolted onto the frame
On the wifes 94 dodge ram truck, i found the ground wire had rotted away where it bolted onto the frame
deepNdirt
Veteran Member
Here is a wiring diagram, and a cheap tester I use to help troubleshoot trailer lighting problems,
MF 1532
Gold Member
I sell trailers , the above posts are all good places to start , ground . I have people hook up to a trailer and I hear ''somethings wrong with the trailer wiring '' . For 6 or 7 $ I have 3 different test plugs I can plug into their truck , and I don't recall it ever being the trailer . The first time I had someone state their dome light in the trailer didn't work was the head scratcher . Now I know to look at truck auxillary trailer fuse . Some manufacturers put a dummy fuse in . Anyway if you ' ll pickup one of those testers life will be simpler .:thumbsup:
