trailer lights

[samthecarman]

hey everyone,

this is kind of off topic but i figured there were enough people that had expierences w/trailers that i could get an answer here, and there is no general electrical boards on AF, that i could find. anyway here goes, i am helping a buddy hook up his trailer lights and we have everything working but the parking lights (turn signals, brake lights, hazards, but no parking lights), the bulb fillaments are good and there are dual filament bulbs in the tail lights in the trailer. the trailer is a home depot trailer and very small, 4 wire connector w/5 wires. according to the diagram the white wire on is the ground, however it runs to the left middle light (marker light). the white wire only runs to one side. put the multi-meter on the wire and got about .04 ohm resistance (although sparatcic) checked for breaks in the wire (there were none), and even ran a jumper wire to see if it changed anything. It did not, and the connector was old and replaced that also. the truck is a brand new nissan titan, and could not find anything wrong with the connections on the truck. can anyone think of anything i forgot to look for ? i consider myself pretty automotive savy and this is exteremly annoying. thanks for everyone's help.

p.s. the trailer is small enough where there are no fuses on the trailer (8ft long trailer 5ft wide).

sam

[JaVeRo]

Take the bulb out and check the voltage between each of the two contacts and ground. When you are checking to ground use the bulb socket then use the trailer frame and also use the white wire.

The current could be going from the brake light to ground but then has nowhere to go so it backfeeds from the housing ground thru the tail light filament and the tail light wire to the truck then thru the truck tail lights to ground.

One way of spotting this is to turn on the tail lights and then turn on one blinker. If your lights start acting funny then it's the ground.

James

[samthecarman]

well, there was another vehicle that was brought over, (jeep), and when plugged up it worked just fine, so I have concluded that it has something to do with the wiring on the truck and not the trailer. i guess that is another issue i need to figure out, thanks for the reply.

Sam

[jocat54]

Don't know about Nissan but I used to have an Isuzu Truck and you had to have a convertor at the trialer hook up on the truck (don't really remember what it is really called). You could check with the auto parts store and they could probably tell you

[Bob B]

Originally Posted by jocat54

Don't know about Nissan but I used to have an Isuzu Truck and you had to have a convertor at the trialer hook up on the truck (don't really remember what it is really called). You could check with the auto parts store and they could probably tell you

You can also get the converter at U-Haul. But that is to correct the separate direction/stop lights from european to the combined light in most U.S. trucks. Nothing to do with the parking lights. If the stop and directions are working, then it must have separate lights for them.
The parking lights are straight forward. You might take a 12 volt jumper wire to the trailer along with a ground, and see which one lights the parking lights then with a volt meter see if the truck is putting out 12v at that pin when the parking lights are on.
Bob B

[samthecarman]

well figured out it was the wiring harness on the truck, somehow the wire that was in the connector attached to the hitch got loose or broke, anyway it is under warranty so my buddy is going to take it to the dealer to get fixed. thanks for all the responses.


sam