bob95065

I am wiring the 3rd brake light on a camper shell I bought for my truck yesterday. I want to use the 7 round connector that is in the bed of my truck. I am using this connector because I don't have wires for the shell on the truck and I want to take advantage of the positive line in the bed for power when camping.

The 7 round connector has pins for left and right turn signals and the brake controller, but not the brake lights. How do I go about wiring the 3rd brake light from the 7 round connector?

TIA,

Bob Elliott

SIXSLUG

It was easy to tap into the brake light wire on mine and run it up behind the brakelight thru the hole in the stake holder. The 7 pin won't work for your third brake light as it cuts out power to run the turn signals off the same circuit.

I believe the center pin in the 7 pin is the constant hot pin. Check it with a multi meter or test light. This wire is large enough to run an aux outlet into your canopy. I have a three hole outlet that accepts cigarette lighter type plugs.

bob95065

What is the stake holder that you mentioned in your post?

The constant hot isn't the center pin. The center pin is for back-up lights. Check out this web site: http://www.myrv.us/electric/Pg/trailer.htm The +12V pin is #4 or black.

I have a headache rack with brake lights and turn signals that is on the truck most of the time. I ran wires for the lights from the cab to a couple of flat connectors I got at the junkyard. I have a second set of connectors for the shell. I will run the brake light and dome light from the rack connectors.

Because my shell wiring is at the tailgate I need to come up with a conduit and 8' of wire to go to the front of the shell. I also need to drill a hole to run the wires out to the existing connectors. I also need a way to mount the conduit so it doesn't move. I was trying to avoid these things.

Does anyone know how they wire shells when they are bought new?

Homestead

Your truck should have a CHMSL (central high mount stop light) pig tail hanging out of the wiring harness underneath the truck on the drivers side right near the spare tire.

It is just a single wire, white I beleive, about 3 inches long. Like I said, it is just hanging there sticking out of the harness under the truck. When new, the wire did have a small tag on it that said CHMSL but over time, the tag tends to vanish.

When you step on the brakes, this pig tail powers up to operate a bed shell brake light.

Every Dodge truck since 94 should have had this pig tail under neath in the harness, every truck I have ever played with has had it.

Jeff

SIXSLUG

The stake pocket is along the side rails of the bed. There is a hole in it that goes into the dead space behind the tailights. its very easy to tap into the brake light wire here and run it into the bed to attach to the wiring harness on your canopy. Mine have always been on the left rear corner and I have had quite a few different ones over the years.

Usually the roof of the shell, if fiberglass, is thickened to support the weight and keep it from sagging. Some higher end shells have a conduit, usually pvc pipe along this area to run wires to lighting at the front of the canopy. A simple solution to get the wires forward is to run a 1/2" or less pvc along the base of the canopy frame rail. You can attach it with electrical clips or epoxy it in a couple places.

As for your 7 wire, sounds like you got it figured out.

roysleight

Homestead is correct. There is a wire specifically for that sticking out of the wire harness in the back near the hitch.

bob95065

OK. I have it now. This is easier than I thought.

I crawled under the track this afternoon and didn't see the CHMSL wire. Then again I was looking at the center of the truck between the spare and the rear bumper. I'll check the left side of the truck tomorrow. Anyone know of a picture of this wire's location?

I think I'll run a hot line back from the after market breaker under the hood that the DPO put there for the hot line to the 7 round connector. I would rather run a wire back than splice into the 7 round wiring. I don't like splices that could short out in the weather. I'll run this line back to the rear left stake pocket and up to connect to the shell. I can find a clean ground on the underside of the bed and I am good to go. Before reading this post I didn't remember that the stake pockets were open to the underside of the truck.

I'll leave the 7 round connector in the bed open for a lighter adapter I made. I sleep with a CPAP machine when I camp that takes a 12v input. I have an adapter I made that plugs into a lighter.

That being said I should be all set. Thanks for the info and TIA for any pictures of the CHMSL wire.

Bob

bob95065

I couldn't resist and went out to the truck with a flashlight. No CHMSL wire that I could see. Did they tuck it into the wire loom or is it hanging out? Can anyone take a picture of its location?

BTW I have a 1997 model truck.

infidel

The highly competent outfit that installed my canopy said no.
Not sure which year the CHMSL wire in the rear came about but on my '95s the only way to hook up the canopy brake light was to run a wire all the way from under the dash to the rear.
Since installing the canopy was free I highly doubt they would have run the wire if they didn't have to.
In fact the installer was cussing that Dodge was the only brand that required the extra work.

bob95065

I lowered my spare and looked all over the back of the truck including the left tail light area and found no wire labeled CHMSL or any lone wires that terminated. I also opened the loom and found no white or tan wires. I think I will be stuck with running a wire back for the stop light.

roysleight

Finally got the picture approved so I can post it for you. This is looking up, you can see the spare tire and frame. The white wire is the one you want. It was sticking out of the wire loom just a few inches when I was looking for it. I don't recall whether it had a label on it. Hope that helps.

BarryG

My truck is not as old as the op's so this may not apply but it had the pigtail and it was labeled chmsl with a tag on it and was in the location pictured above. Do not remember it being white am thinking it was tan colored and maybe 6 inches long.

bob95065

Guys, thanks for the help especially the picture. I took the wires out of the loom in the location in the picture and did not find a solitary wire or a light colored wire. They are all black with colored tracers and none terminate in the loom. I ran a wire back from my brake light switch and the 3rd stop light works great.

SIXSLUG

Nice work!