Factory Trailer Wiring

[grumpin]

Red/light green should be the ignition switch to coil wire.

Interesting that they’re the same color.

 

[grumpin]

Definitely what page 77 looks like.

What is the 'chassis cab and flareside only' box beneath the 'trailer only' referring to?

I believe that’s the difference in the drawing, chassis cab and flareside only, no trailer light option. Trailer only with the option.

 

[85lebaront2]

I still think R/LG is when you use the controller to use the trailer brakes only, not pressing the truck brake pedal.

On mine I believe the LG wire is the brake lights, I know I can "brake check" a clown who is dumb enough to put his little POS Jap or Korean crap on Darth's bumper by simply pushing the knob to the right. Red is power, Blue trailer brakes, White ground (not really needed on mine) Light Green is brake lights. FWIW, the 1992-97 PDC has two dedicated fuses for trailer stop and turn, they are slaved off the truck rear lights in the PDC. I went one better, due to previous experience and added two more relays, one for each side so a dead short in the trailer harness or trailer will only kill those circuits.

[kramttocs]

Definitely what page 77 looks like.

What is the 'chassis cab and flareside only' box beneath the 'trailer only' referring to?

I believe that’s the difference in the drawing, chassis cab and flareside only, no trailer light option. Trailer only with the option.

I get the trailer wiring is only with the Trailer Option but what is the chassis/flareside specific piece in the diagram that doesn't apply to stylesides (off topic likely but would like to know)?

So turns out for my truck that tracking down R/LG doesn't seem to matter. I started to do some continuity checks but after all of them failed I realized I hadn't routed and connected all the wiring under the booster

While I was by the rear bumper looking at the 7 way plug I notice up near all the connectors there was a R/LG wire with a female barrel connector not connected to anything.

I had actually dug dirt out of the connector and stuck a male plug in there to keep it clean right after I got the truck but had forgotten about that.

Looks like it's a second way for the lights as you said, Dane.

I'll let it go for now until I get power back in the truck and test it out.

Thanks all!

As a side note, did get the brake controller installed and will cover that in the build thread later tonight.

[kramttocs]

On mine I believe the LG wire is the brake lights, I know I can "brake check" a clown who is dumb enough to put his little POS Jap or Korean crap on Darth's bumper by simply pushing the knob to the right. Red is power, Blue trailer brakes, White ground (not really needed on mine) Light Green is brake lights. FWIW, the 1992-97 PDC has two dedicated fuses for trailer stop and turn, they are slaved off the truck rear lights in the PDC. I went one better, due to previous experience and added two more relays, one for each side so a dead short in the trailer harness or trailer will only kill those circuits.

Does that not also apply the trailer brakes?

[grumpin]

I get the trailer wiring is only with the Trailer Option but what is the chassis/flareside specific piece in the diagram that doesn't apply to stylesides (off topic likely but would like to know)?

So turns out for my truck that tracking down R/LG doesn't seem to matter. I started to do some continuity checks but after all of them failed I realized I hadn't routed and connected all the wiring under the booster

While I was by the rear bumper looking at the 7 way plug I notice up near all the connectors there was a R/LG wire with a female barrel connector not connected to anything.

I had actually dug dirt out of the connector and stuck a male plug in there to keep it clean right after I got the truck but had forgotten about that.

Looks like it's a second way for the lights as you said, Dane.

I'll let it go for now until I get power back in the truck and test it out.

Thanks all!

As a side note, did get the brake controller installed and will cover that in the build thread later tonight.

My bad! I was thinking styleside in my head, but that’s not what it says.

Well... now I’m curious!

Edit: Unless it’s for connectors C354 and C355.

[85lebaront2]

Does that not also apply the trailer brakes?

The Kelsey-Hayes hydraulic controller has two internal contacts, one simply turns on the brake lights and comes on with very little motion of the lever, the second is a variable resistance, the further the lever moves, the greater the applied voltage. The brake light contact makes before the brake magnet feed, also I use that when running without anything behind or with my Aluma open cargo trailer which does not have brakes. Purpose is to scare the clowns that like to tailgate thinking their 2000 lb Honduh or similar is going to intimidate me in a 6400 lb crew cab DRW truck.

Years ago, taking our oldest son to Atlanta to attend DeVry there, we were going down I-85 passing a long line of slower vehicles a Honduh got right on the back bumper, my wife asked "aren't you afraid he might hit us?" I informed her that if he did, the class 3 receiver hitch under the rear bumper of a roughly 5000 lb empty weight 1971 Colony Park wagon would do more damage to his car than he could think of doing to ours. After a few miles, I think the reality of the wagon tailgate being bigger than the front of his car and the facts that (a) I wasn't paying any attention to him and (b) was running 5 mph over the 75 mph speed limit he dropped back and just sort of drafted us till we passed the line, at which point I went back to the right lane.

[kramttocs]

The Kelsey-Hayes hydraulic controller has two internal contacts, one simply turns on the brake lights and comes on with very little motion of the lever, the second is a variable resistance, the further the lever moves, the greater the applied voltage. The brake light contact makes before the brake magnet feed, also I use that when running without anything behind or with my Aluma open cargo trailer which does not have brakes. Purpose is to scare the clowns that like to tailgate thinking their 2000 lb Honduh or similar is going to intimidate me in a 6400 lb crew cab DRW truck.

Years ago, taking our oldest son to Atlanta to attend DeVry there, we were going down I-85 passing a long line of slower vehicles a Honduh got right on the back bumper, my wife asked "aren't you afraid he might hit us?" I informed her that if he did, the class 3 receiver hitch under the rear bumper of a roughly 5000 lb empty weight 1971 Colony Park wagon would do more damage to his car than he could think of doing to ours. After a few miles, I think the reality of the wagon tailgate being bigger than the front of his car and the facts that (a) I wasn't paying any attention to him and (b) was running 5 mph over the 75 mph speed limit he dropped back and just sort of drafted us till we passed the line, at which point I went back to the right lane.

Thanks Bill. I've used the lever when testing the brakes but don't think I have when driving so was curious. The two contacts makes sense.

[kramttocs]

Thanks Bill. I've used the lever when testing the brakes but don't think I have when driving so was curious. The two contacts makes sense.

Here are the factory trailer wiring connectors.

Note that C1110 is a standalone harness that goes from under the brake booster (where it goes through a grommet into the cabin to connect to a brake controller) to the rear crossmember. This harness includes the black Trailer Lamps circuit from C1104.

[Gary Lewis]

Here are the factory trailer wiring connectors.

Note that C1110 is a standalone harness that goes from under the brake booster (where it goes through a grommet into the cabin to connect to a brake controller) to the rear crossmember. This harness includes the black Trailer Lamps circuit from C1104.

Good documentation. Thanks, Scott.