No Power At Trailer 7 Pin Connector

MDSilverado · October 18, 2009

I just plugged into the trailer plug for the first time and no power. I have checked the fuses under the hood and all appear to be OK. I have used a voltmeter on the female socket on the back of the truck and don't have power. Does anyone have any suggestions. I don't want to take it to the dealer to find I was doing something stupid or had a blown fuse and didn't know it. The fuses under the hood all seem to be for trlr stop and turn. I didn't see one for auxiliary?

Any suggestions?

AK FiveO · October 18, 2009

I just plugged into the trailer plug for the first time and no power. I have checked the fuses under the hood and all appear to be OK. I have used a voltmeter on the female socket on the back of the truck and don't have power. Does anyone have any suggestions. I don't want to take it to the dealer to find I was doing something stupid or had a blown fuse and didn't know it. The fuses under the hood all seem to be for trlr stop and turn. I didn't see one for auxiliary?

Any suggestions?

I have only used the standard "4-pin" (w/7-pin adapter) on my 2009 Sierra. However, i know on the ford trucks you always had to go in and add the "trailer harness" relay under the hood. The relays came with the trucks ...in the glove compartment when they were new. Dont have a clue why ford just didn't put them in? Anyway ...those relays added the other pins like "trailer battery charge", "trailer brakes" and trailer back-up lights"

I suggest you look in the manual under "fuses and relays" ...make sure all the ones for trailering are actually inserted in the trucks fuse/relay panels.

ffthornton · October 18, 2009

There is a wire already under the hood you have to hook up and add a fuse toget aux power. There is also another wire for trailer brakes. If I am not mistaken its the wire close to the break buster. And i believe its labled. It will be wound up in that area.

MDSilverado · October 18, 2009

OK so I see now that there some wires left unconnected under the hood for the seven pin harness (see below). So, do I really need to go pay the dealer to finish connecting my harness. Is there a "how-to" on the forum somewhere that could walk me thorough this? Any help would be appriciated...

compulynx · October 18, 2009

Prodigy Install Info

This has the info you need in it. It is a full brake controller install, but shows you where the aux wire is. See step 19

C

MDSilverado · October 18, 2009

Prodigy Install Info

This has the info you need in it. It is a full brake controller install, but shows you where the aux wire is. See step 19

C

Great write up. I see exatly what I need and I'm going to be getting the Prodigy so this will be great to have around.

Another question...below is pic of the cover of my 7-pin socket. Why is it different than the pinning in you diagram in 37. Even more confusing is that it doesnt match the diagram I was given for the (used)trailer I bought?

compulynx · October 18, 2009

Prodigy Install Info

This has the info you need in it. It is a full brake controller install, but shows you where the aux wire is. See step 19

C

Great write up. I see exatly what I need and I'm going to be getting the Prodigy so this will be great to have around.

Another question...below is pic of the cover of my 7-pin socket. Why is it different than the pinning in you diagram in 37. Even more confusing is that it doesnt match the diagram I was given for the (used)trailer I bought?

It depends on which connector you are looking at, the truck or the trailer connector....They should all be wired alike. Also whether you are looking into the connector, or from behind it...I know it can be confusing. The diagrams in the install info are looking from the back of the connectors, not into them...

If you will look at the 7-way trailer end diagram in the install info, you will see it matches the one on your cover....

The center pin is more confusing, but it is not used in most cases...

C

thearborbarber · October 18, 2009

What pins are different between you trailer and vehicle connector?

MDSilverado · October 19, 2009

What pins are different between you trailer and vehicle connector?

Most all it seems. Am I looking at this wrong. I assume I have to spin the two diagrams so the locator notches align? When I do that the truck has + the trailer cable is brakes.

I think the best thing to do is grab the old trust multi meter before I plug it in and make sure I got the pins right. Shouldnt be too hard.

thearborbarber · October 19, 2009

That would be the best idea. My father in law has a trailer that as a "custom" wiring pattern and it's pain to deal with when he has lighting trouble.

compulynx · October 19, 2009

What pins are different between you trailer and vehicle connector?

Most all it seems. Am I looking at this wrong. I assume I have to spin the two diagrams so the locator notches align? When I do that the truck has + the trailer cable is brakes.

I think the best thing to do is grab the old trust multi meter before I plug it in and make sure I got the pins right. Shouldnt be too hard.

Ok, I see where you are getting confused. That little notch at the bottom is NOT the outer notch on top. It is a notch where the ceramic connector aligns with the metal housing of the connector handle(The part you push in with)

Here in red is where the Keyway would be....

Hope this helps. Just try to remember the Keyway is on top, so most diagrams will be oriented that way...

C

MDSilverado · October 19, 2009

Yep...that was the problem. I kept trying to spin it assuming the releif was the alignment groove. It all looks right now. I'll give it a try tomorrow night.

Thanks Glenn & Chris!