trailer wiring problem

McCracken

McCracken

Logan Can't See This
Joined
Jul 9, 2005
Location
With your mom at a nice seafood dinner
First off I have a 99 PSD if that makes a difference. the problem is that I'm not getting anything on the left (driver) side of the trailer. I checked the plug and it's not getting voltage either. I just went and picked up a new plug from Wally World. The plug was supposed to plug into the truck but the PO cut the plug from the truck and wired in a 4-pin connector instead of 7-pin. I cut his BS out and wired the 7-pin in. I'm pretty sure I wired it correctly. What sucks is that it was doing this before I installed the new plug and now it has the same problem with the new one. What gives?

If anyone knows about the back end of a PSD there's a plug above the spare tire and it leads to another plug that plugs into the new one I bought at Wal-Mart. Confused yet? Well, the only thing I know to do check the plug comign from the truck and see if it is hot or not. Any other suggestions?

One other note. He wired in a brake controller in the cab. Looks fairly neat but I don't know how that might have affecting the lights. Can it?

Thanks for all the help.
 
first things first, check the fuses, there are seperate fuses for the left and right stop/turn lights, if all lights are working except left turn then that would be my first bet.
 
there are separate fuses for the trailer harness, left and right. The lights on the truck will work if these are blown, just not the trailer. 10 amp, I think number 13 and 14 in the box under the hood (not the in-cab fuse box). Look in your owners manual.

HTH,
Shannon
 
Ok have you started tracing to the problem?

You know its bad at th trailer so work forward from there.

Take a test light to the connector (with trailer unplugged) that will tell you real quick if problem lies in trailer or plug forward.

Given what you said I would be willing to bet you that the wiring to that plug is bad.

Not 100% sure on yours but on the 99 PSD and both 04 F250s had both 7 and 4 pins factory. But I cant swear that it wasnt an option of sorts. (all 3 had the factory towing package)

As to the break controller. It shouldnt bee your problem. the truck comes with a harness that plugs in under the dash and wires color for color to any controller
 
I just wired the plug in myself. All connections are tight. I tested the plug and I'm not getting anything from the second prong from the top. The right side gets it but the left side no.

I thought the plug was bad too so I put a new one in it and I still have the same problem. Pictures might be best here. I'll snap a few of the situation and post up later.
 
I gues I am wondering if your wiring was done correctly. Not if the connections are good but if the schematic is right.

You need to pin out your connectors.
Find where you need power on the trailer to make what happen.
You could do this with a short piece of jumper wire.
 
well, i checked the fuses again just to make sure and i found something. there was a hair line break in one of the 7.5 mini fuse under the hood. this might be my culprit.

anyway, here's the plug I was mentioning.

DSC02357.JPG

DSC02358b.JPG

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DSC02360b.JPG

DSC02361b.JPG


sorry, some are blurry.
 
OK,
Look at your next to last pic.
You can easily see the 7 pins
2 on the bottom
2 on the left middle
2 on the right middle
1 on the top right

Now without even googling I cant tell you what is where.
But a test light and a few minutes, plus a helper to push the brake pedal you can pin that out quickly.

Also check your fuses with a meter/light dont depend on your eye.
 
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