My battery does not charge. During trouble shooting I found no power to my stock Ford trailer connection. I found a 4 pin plug near the power distribution box that is not connected to any thing. I check continuity and this connector is the one that goes to my trailer power.

Where do I connect this plug into?

 

A week with no replies.....maybe the folks in the towing forum can shed some light n the problem. Thread moved.

 

Is your truck's connector round with 7 pins? If so, you may need to add a relay to get pin 4 hot with the key on.

Steve

 

I have a 25' Jayco Travel trailer with a double axel tandum setup, electric brakes, a stabalizer bar, and my rig charges two batteries on the trailer. I would recommend that you go to a Travel trailer dealer. They do this ever day and will be able to isolate the problem in just a few minutes. Also, they do not charge you an arm and leg to fix your problem because they want your maintenance business in the future.

This probably isn't the answer you want, but it is the best quick fix done by someone who does this everyday.

Mert from Littleton, CO

 

If you have not installed the relay and fuse to activate the trailer tow, then, no you will not have power. You'll need to consult the manual, but you will find that you need to install two relays with the appropriate fuses along with make sure the trailer brake fuse is installed and you'll be good to go.

 

Am I reading this right?

This plug is just hanging up there by the power distribution box and it has continuity to the charge pin at the trailer charge pin on the plug at the back of the truck.

Does that connector look like a relay might sit on top of it? If a relay plugs into it, it should be square and probably have four female connectors on it. Two should be hot when you have your key in ON and there should be one Ground.

Most Ford connectors are keyed so you can't normally plug it into the wrong receptacle.

Otherwise, I'm plum out of ideas unless I can stumble across a wiring Cookbook from that era of trucks.

 

The 4 pin flat connector is supposed to be piggy backed for running, left/stop, right/stop, and ground. I am not sure if your truck has an aux relay bank under the hood like the newer superduties do. I would think that it would. Is there anything in the manual in the fuse section that identifies any of the relays as trailer tow charge or the like?

 

yes, the plug is capped @ the power distribution box. this truck should have had the relays installed from the factory. it has the stock ford 7 pin trailer connection. the trailer brakes work.

the guy that installs the relays must have took a long break.

 

I've got an electrical manual for a 1992 F Series Truck.

For the trailer towing harness with a diesel in those days, it says that your trailer battery charge relay should be located in the power distribution box. The connector for the relay has four pins (well, receptacles since the relay has the male ends) and four wires. The color mapout is purple/orange, black, yellow, and orange. P/O is the trip for the relay, yellow is 12 volts from the 30 amp trailer battery charge fuse, black is ground for the relay, and Orange is the 12 volt supply that goes all the way back to your trailer connector out back.

I know that the orange wire has been the same for ages on these trucks, as the batt charge wire on my 04 is still orange.

The mannual for the 92 shows a path through four connectors, two of which are right on the firewall and have many pins. The only 4-pin setup shown is under the truck. I gather Ford made some changes along the way between 1992 and 1995.

It's hard to say whether Ford just goofed on the truck or whether they left it to the dealer to put in those relays. I've seen a few trucks in my time that just had a plastic bag from Ford in the glovebox that had a brake control pigtail and two relays. Perhaps the baggie got lost somewhere along the way. Who knows?

The trailer towing package is also supposed to give you a trailer backup lights relay in your power distribution box, by the way.

Best of luck with your project.