No lights in the trailer...need help

[KBertetto]

Fellas, I hope someone here can point me in the right direction. I have a 27' Haulmark cargo trailer that I'm going to pull down the ALCAN in about 6 weeks. Come to find out, the interior lights will not work when the electrical connection (7 pin) is connected to my truck. When I connect it to my neighbors Ford, they work perfectly. Obviously not a problem with the trailer if they work with the neighbors truck... whats wrong with mine? Everything else works fine, it's just the 2 interior cargo lights that won't work. Thanks



Kevin

 

[boatpuller]

Good wiring schematic for your trailer plug is available here,

http://www.marksrv.com/wiring.htm



it sounds like you don't have any power to your battery charge lead, pin number 4, if that's where your trailer gets it's power from.



See which pin on your neighbors truck has power that your truck doesn't, would be the easiest way to troubleshoot.

 

[duckcarvr]

The two times that has happened to me i just cleaned the plug and receptical. plug it in and out several times see if that helps. robert

 

[Hoefler]

Check the fuse in the hot line for the trailer.

 

[jelag]

This circuit on your truck is a fused circuit..... As I remember the charge line to the trailer connector is a 15 amp circuit. I'm guessing that you've either overloaded it at one time or grounded it... . check the fuse first... Most of the Dodge PU's I have list the pin out information on the black cover of the plug... . if so. . use either a test light or DC Volt meter and test the pin at the trailer connector at the back of the truck...



I have a large trailer and when the batteries are down they often overload the trailer plug... . I've run a Fused 10 gauge wire from the battery to the back of the truck to the trailer plug and my trailer lead wire has a 10 gauge 12V + and - in the cable to handle the load... .



Works for me... Hope this helps. .

 

[RustyJC]

Does your trailer have electric brakes with a breakaway switch? If so, the interior lights should be powered off your trailer battery even if the trailer is not plugged into a truck. If your trailer battery is missing, your trailer brakes won't work in the event of a breakaway.



Just something else to check out...



Rusty

 

[KBertetto]

Thanks alot for all the replies/help, highly appreciated. Friday morning I will start the investigation to see whats happening. I just checked pin 4, and there is no power there, my neighbors truck does so thats my problem. My trailer does have electric brakes with a breakaway, and that system works fine. It is run off a really small 12v battery... half the size of a motorcycle/atv battery. I'll be checking all the fuses and and everything else, hopefully it's something simple. Again, thanks for all the help fellas. TDR membership really does pay for itself one way or another.



Kevin

 

[LEPage]

My money is on the wire being corroded in the plug on your truck.