My dad wants to install an additional reverse lamp on this truck has the towing package. I won't let him wire it to a manual switch because he WILL leave it on while driving around. It needs to be connected to the reverse circuit somehow.


First choice it to run off the trailer reverse relay. The relay in #203 works since I can feel it click when shifting in and out of reverse. There is the standard round 6-pin connector at the back, but none of them are for reverse. There is a smaller (~1"?) hole next to the license plate like maybe there was another connector there at some point, but I looked under the truck and can't find anything disconnected. Where does the trailer reverse lead go? If I have to pull the engine bay fuse box up, I will, but I'm hoping you guys have an answer.


Plan B will be to tap into the reverse circuit at one of the taillights and run a relay off of it.

 

Run a wire from the factory reverse lights to a relay.

 

Only trucks I have seen that have a reverse are the typical 7 pin connectors. But like IBD said just tap into the factory reverse circuit to trigger the relay.

 

If it has the 7 pin in the back already it should be the purple wire which is also the center pin if i remember correctly.

 

He has the starndard 6 pin, which doesnt include a reverse feed.

 

There might be confusion on 6 vs. 7 pin. There are 6 radial pins and one contact in the center for a total of 7. Also, the radial pins are flat versus round like some trailer plugs seem to be. When we were messing with the truck, I did a quick pinout search on my phone and nothing showed a reverse and the center didn't seem to have a purpose or was cryptically labelled "auxiliary". Now that I search again, I'm actually finding that the center post could possibly be reverse like 20004X4 mentioned...



His multimeter leads started going out so I didn't want to use it to probe, but I'll have to bring mine over and find out.

Since the truck already has a relay for this tucked away in a nice OEM, weatherproof spot, I would rather utilize that than have to source a weatherproof relay and plug, mount it, and splice into the factory wiring. The less molesting of factory wiring, the better.

 

You might like to know that is the access hole to lower your spare tire, .

 

LOL.


That explains the plastic cone above the spare, too. Thanks.

 

The OEM relay is not for reverse it is to carry the extra load on the electrical system due to running lights and brake lights.

 

There any a few delegated to trailer duty and #203 is specifically for trailer reverse according to the owner's manual.