any way to test trailer lights w/o truck hooked up? (flat 4)

[Dabba]

yeah, i could borrow my stepdads ranger, but its stick, and while i dd a stick im not quite used to the truck and id have to back it up a hill to the trailer, dont wanna bump it and dmg the truck or knock it loose. im waiting on the military to flat 4 adapter for my cucv but i was wondering if theres some ghetto way to test the lights? i was thinking of just applying a 12v power source? and assuming i could do this, would it just be testing the lights or could i test the brake/signal fuctions? if i could it would be good to know in case lights dont work with my cucv, ill know its the truck. thanks

 

[BobK]

Yes, just apply 12+ to the wires you wish to test.

If it's your typical trailer harness:
White- Ground
Yellow-running lights
green- turn signals
brown- turn signals

 

[Dabba]

wow thanks, i was thinking of doing it off the battery of my truck, thanks

 

[t89blazer]

I think you will also have to ground the battery to the trailer.

 

[Fordum]

Look at the plug. The one male pin, is hooked to the white wire. The white wire should be hooked to the frame of the trailer. If not, hook it up. You will be glad you did later when a dirty hitch ball does not cause your trailer lights to flash.
Then, just hook the ground of a car battery to the male pin, and hook the positive to the sockets in turn. One will cause both tail lights and any marker lights to come on, the other two will cause the brake/turn signal lights on each side to come on.

J.

 

[Jason4x4]

yellow is left turn/brake
green is right turn/brake
brown is running lights

 

[Dabba]

thanks guys, couldnt get it to work, prob cause of corrosion, borrow the stepdads truck to test it and it works, thanks

 

[badmix]

Make sure you got good grounds. I would run a ground from the trailer to the truck seperate from the rest of the harness, to test and to use., otherwise you could be chasing light issues when there isnt any issues at all.

 

[Dabba]

yeah coulda been that too, but when i used the actual hookup and ground it worked so imhappy. Now lets hope my cucvs trailer wiring hookup is intact..