I have been redoing a 79 long bed and repairing the wiring harness has been very challenging. I have been unable to locate these wires in any diagram that I have found. Can someone please tell me what these are for?

 

The four blue wires with the plug on the end are for the speakers and plug into the radio. Assuming the wires in your hand in the first image are for the heater switch then I'm not entirely sure what those remaining cut wires do.
They look like they go together so what happens when you connect them? Maybe your truck had a factory tape player in addition to the radio?

 

The wires in my left hand are the stereo power, ground, and speaker wires that have been added. There wasnt a heater control in the truck when I got it, is it possible the cut wires go it? Does anyone know the wire color or what the plug looks like going to heater control?

 

I'm still looking at my harness out of an 81, so I may come up with some answers. It appears that the 3 prong plug in the center of the first pic goes to the heater unit on the left side.

 

How many plugs go to the heater control on your 81?

 

I looked at the heater box itself. You have a 3 prong plug that goes into the left side of the heater box and above it there is a two prong connector that hooks up to the wiring harness. There also should be a Four prong plug from the harness that hooks to the blower speed switch. I'll have to pull my harness out of storage to get you some wiring colors. The switch should be have White/Black, Lavender/White, Lavender/Yellow, and Lavender/Black. from the harness. I took those colors from the 83 FSM, you can download it from up in the Stickies above in the Forum. It has a section on BODY Electrical and Troubleshooting that might get you some info on hookups.

Don't be surprised to find plugs that were not used. They were for the different options that you truck didn't have, but they use a generic wiring harness for all

 

 

The heater switch plug may have a Blue/Black, Blue/Yellow, Blue/White wires plus a ground wire, according to my wiring diagram. You can see my switch in the lower right corner


You never said if your truck was a 2 or 4 wheel drive, stick or auto. If auto, then there should have a neutral safety switch, with two Black/White wires.

If stick or 4WD, then there should be a 4WD switch plug with possibly a Green and a White/black wires. Also, my Backup light switch wiring running through the floorboard has a Blue and a White wire. Below are the plugs, Backup on left and 4WD on the right. Hope that helps ya

 

BTW. I can send you my 81 wiring diagram that I use, and some pics of my under dash tear down for reference. Just send me your e-mail addy via a PM

 

The 4wd switch is the green and white/black wiring that I was unsure of. Can you confirm that the blower switch is 3 or 4 prong? Great information and pictures thank you!

 

My switch connector is 4 prong with Lavender/Black, Lavender/White, Lavender/Yellow and a White/Black wires. The connector is square-ish with locking clip on the top. Note: Some of the Lavender colored wires will look like blue in it's old age

 

Can anyone tell me the location of the wiper control module? If it is supposed to be in the passenger kick panel then I know why I cannot find my heater blower switch wiring.... my wiper module is plugged in beside the gauge panel.

 

Are you asking about the Wiper relay? If so, it should be above the passenger kick panel. You might remove the glove box to see it easier and bolted to the metal fairing. There are two black "box like" relays in that area, the turn flasher is the larger one.
E-mailed you a .zip file that will help part locations and part number. It covers 1980, but should help

 

Lons81 thanks again you have helped me tremendously with the information you have given me. At what point in my trucks life the wiper relay made it's way from the passenger kick panel to the fan switch connector is far beyond me. That really does show some of the crazy stuff I have sorted out thus far.

 

Just FYI for you for stock install location
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I had a metal box style flasher that was no good so i converted it over to a ep35 style flasher. I have it mounted in the in the factory location for the wiper relay. The mounting bracket / back of wiper relay is missing so I will have to be creative in protecting the circuit board and mounting it.