No volts at trailer socket.

[Kchula-Rrit]

This is not strictly a Forest River issue, but I thought I would ask anyway. I wired lights for a trailer to tow behind my 1994 Grand Caravan, which has a seven-pin connector like the rest of our vehicles, including our Sun Seeker.

The wiring kit came with a four-pin coupler about three feet from one end of the cable. After wiring the trailer lights I took a seven-pin plug I had laying around and made the appropriate connections for running lights and brakes/turn signals.

Realizing that I had just made a seven- to four-pin converter, I unplugged the four-pin coupler and took it out to plug in to the back of my car to check that everything worked and went to "the right places." My reasoning was that I would not fry either the car wiring or the trailer wiring. Also, the car was parked at the curb and the trailer was in the garage.

After plugging-in my home-made adapter, I turned on the running lights and cycled the turn signals while I used a DVM to check for voltage that would go to the trailer. I got nothing on any connections. Then I went to our Jeep, which has a socket that I know works, because we pulled our cargo trailer with it a couple of weeks ago. Same result, no volts.

Any ideas? Do these things need a load to show voltage? I figured that there would be 12 volts on the pins when the lights are supposed to be lit.

I'm thinking of plugging the Caravan into the cargo trailer to see if the socket works.

Thanks in advance--

K-R.

[wmtire]

Originally Posted by Kchula-Rrit

After plugging-in my home-made adapter, I turned on the running lights and cycled the turn signals while I used a DVM to check for voltage that would go to the trailer. I got nothing on any connections. Then I went to our Jeep, which has a socket that I know works, because we pulled our cargo trailer with it a couple of weeks ago. Same result, no volts.

Any ideas? Do these things need a load to show voltage? I figured that there would be 12 volts on the pins when the lights are supposed to be lit.

When using the multi-meter to check for 12 volt DC at the socket terminals, how exactly are you doing this?

Did you make sure to set the multimeter for the appropriate dc voltage setting, use the red probe to check the terminals, while making sure the black probe was touching a good ground source..which it has to be? I usually use the connectors/socket ground terminal for this.

[Kchula-Rrit]

I used the ground on the socket. The only thing I can think of is that the ground lug I used was open. I've seen transistor circuits, for example, that require pull-up resistors; these won't show the right voltages without a load.

Anyway, the story has a happy ending. I went back to the place that installed the hitch and told them what happened. The guy came out and connected a second grounding lug that I did not know was there. After I got back, I backed the Caravan up to the trailer and plugged it in. The Better Half watched the lights while I worked the blinkers and brakes. Everything worked!

Thanks, everyone.

K-R.

[Bama Rambler]

Thanks for coming back and letting us know what the fix was. We like getting the conclusion.