SmashBack
Full Access Member
- Joined
- Jun 4, 2013
- Posts
- 57
- Reaction score
- 11
- Location
- Texas
- First Name
- Chris
- Truck Year
- 1979
- Truck Model
- Big 10
- Engine Size
- 6.0
I've been meaning to do this for a long time and finally got around to it this weekend, thought I'd write up another how-to. Nothing wrong with the current ones, but more information is usually better so another won't hurt!
Looking at this and how the wiring is done (mine is a 79, I know there's probably some differences between years) I really wanted to just pull the entire power window harness and start fresh. Mine is in great shape for it's age and I thought somebody else might want to use it for a true resto but meh! Too much work and I could not find reasonably priced connectors/terminals/pigtails to replace the ones needed for the switches and motors.
I decided to use a ground to active the relays, so now I only have one hot wire to each door (for the windows anyway, the locks have theirs as well). That fat (12ga?) wiring they used will carry a ground just fine, and no positive running over the old switches is good IMO also.
Supplies I used:
4x 30a SPDT relays
4x relay sockets
Approx 1.5' 12ga wire (red)
Approx 1.5' 14ga wire (black)
Shrink tubing
2x 1/4" ring terminals (16-14ga wire size)
8x terminals for the relay sockets
Solder, soldering iron
Dielectric grease
Relay pin wiring:
30: Power in from cab, original wire (Pink?).
87: Power out to window motor, each relay will power one window, one direction.
86: Jumper wire, connected to pin 30 wire. Provides power for the relay itself.
85: Ground signal from window switch. This will activate the relay and apply power from pin 30 to pin 87 when the switch is pressed.
I bought a six pack of relays with sockets that clip together on Amazon for about $11 (online led store brand). I am always using relays and this was a decent price so I have two spares now. You can skip the sockets if you want and you can use butt splice connectors but I would not recommend it. My goal was the cleanest install, as few wire splices as possible, moisture resistant, and easy to see what the setup is doing by referencing factory wire colors/diagrams.
Both sides are pretty much the same. Drivers side switch has 5 wires, passenger has 3. One is always hot (when ign switched on) and the others run to the window motors, up and down. On my 79, the passenger switch motor wires run up in the dash where they have a connector that combines them with the drivers side switch wires, so that both switches will send a signal to the passenger side motor. That meant I did not have to mess with anything other than the few wires in the door itself. Double check how yours are configured to make sure you don’t mess anything up by doing what I did!
First thing first, disconnect the positive cable from the battery.
Prep your relay sockets. I removed all of the wires except the white one on pin 86. It’s small gauge and I use it to provide power from the truck coming from pin 30. Crimp, solder and heat shrink a piece of 12ga wire (say 6 inches or so) AND the jumper wire for pin 86 with a terminal, insert the terminal into the spot for pin 30 on the relay. The two wires together will be thick and may be difficult to get in to the crimp fitting. The solder and heat shrink will help keep it neat and together The sockets are done for now and will need two more wires added later.
Next pull your door panel. Decide where you want to mount your relays. You can go ahead and bolt one of them on. The second relay will be held in place by the clip together relay sockets if you’re using them. If not, bolt the other one on at this time. I think where I put mine is optimal when it comes to wire routing. This will ensure you can snip the motor wires and attach them to the relays without adding additional wire to them.
Find the hot wire coming in, probably the big pink one. Snip this a few inches from the switch plug. See where the ground wire is bolted to the door. You’ll want to solder up a wire (I used black 14ga I had in my parts box) to the pink wire stub left on the switch connector that’s long enough to reach that ground point and apply shrink tubing to it. The other end of this wire gets a ring terminal. Using a terminal with the blue nylon sleeve I crimped it and then soldered, the heat from the soldering tends to shrink the sleeve so that it won’t go anywhere, although it’s also not really needed on a ground. Now attach the ring terminal to the ground point.
Next you’ll need to splice the power wire from the cab with the two 12ga wires you installed in the terminal sockets. This will provide power to each relay. I did not trim any from the factory wire but trimmed both of the relay wires down. Strip the insulation off the ends of all three wires and solder them together. Don’t forget to put your heat shrink on first!
Finally, take the pair of wires that run from the switch connector and decide where to cut it. You’ll need both ends of the pair to be able to reach your relays. Cut the wires and split and separate the pairs (a few inches will do) on each side. Strip off a bit and crimp on the relay socket terminals, finish with solder and heat shrink. Since these will live in the relay sockets they don’t really need heat shrink but the wires are a bit large for the common terminals. Adding heat shrink will make sure they’re solid and provide a little strain relief. You can go ahead and plug them in to your relay sockets. Each color is for one direction (up or down) and needs to be on the same relay. When the switch is pressed it will connect the ground from the ring terminal we just installed to pin 85 on the relay. This will power the relay, allowing power to flow from the pink hot wire coming from the cab in to the door which is now connected to 30 on the relay, to pin 87 on the relay, which will now be connected to the window motor.
I packed a small amount of dielectric grease in the relay socket terminals - the top side where the relay plugs in. This will keep them from rotting from moisture. You’ve now completed one door. Do the same on the other side and you’re done! Now we’re putting a lot less strain on the electrical system and those windows go up and down at a decent speed. There may be other improvements to be had by working further up the line so to speak, and I will look at that when I get around to doing my LS swap since there will be a lot of rewiring going on then.
I hope this helps someone and if you see any errors, omissions or room for improvement please say so. I’ll keep an offline copy of this doc and update the post as needed in the future (if possible).
Looking at this and how the wiring is done (mine is a 79, I know there's probably some differences between years) I really wanted to just pull the entire power window harness and start fresh. Mine is in great shape for it's age and I thought somebody else might want to use it for a true resto but meh! Too much work and I could not find reasonably priced connectors/terminals/pigtails to replace the ones needed for the switches and motors.
I decided to use a ground to active the relays, so now I only have one hot wire to each door (for the windows anyway, the locks have theirs as well). That fat (12ga?) wiring they used will carry a ground just fine, and no positive running over the old switches is good IMO also.
Supplies I used:
4x 30a SPDT relays
4x relay sockets
Approx 1.5' 12ga wire (red)
Approx 1.5' 14ga wire (black)
Shrink tubing
2x 1/4" ring terminals (16-14ga wire size)
8x terminals for the relay sockets
Solder, soldering iron
Dielectric grease
Relay pin wiring:
30: Power in from cab, original wire (Pink?).
87: Power out to window motor, each relay will power one window, one direction.
86: Jumper wire, connected to pin 30 wire. Provides power for the relay itself.
85: Ground signal from window switch. This will activate the relay and apply power from pin 30 to pin 87 when the switch is pressed.
I bought a six pack of relays with sockets that clip together on Amazon for about $11 (online led store brand). I am always using relays and this was a decent price so I have two spares now. You can skip the sockets if you want and you can use butt splice connectors but I would not recommend it. My goal was the cleanest install, as few wire splices as possible, moisture resistant, and easy to see what the setup is doing by referencing factory wire colors/diagrams.
Both sides are pretty much the same. Drivers side switch has 5 wires, passenger has 3. One is always hot (when ign switched on) and the others run to the window motors, up and down. On my 79, the passenger switch motor wires run up in the dash where they have a connector that combines them with the drivers side switch wires, so that both switches will send a signal to the passenger side motor. That meant I did not have to mess with anything other than the few wires in the door itself. Double check how yours are configured to make sure you don’t mess anything up by doing what I did!
First thing first, disconnect the positive cable from the battery.
Prep your relay sockets. I removed all of the wires except the white one on pin 86. It’s small gauge and I use it to provide power from the truck coming from pin 30. Crimp, solder and heat shrink a piece of 12ga wire (say 6 inches or so) AND the jumper wire for pin 86 with a terminal, insert the terminal into the spot for pin 30 on the relay. The two wires together will be thick and may be difficult to get in to the crimp fitting. The solder and heat shrink will help keep it neat and together The sockets are done for now and will need two more wires added later.
Next pull your door panel. Decide where you want to mount your relays. You can go ahead and bolt one of them on. The second relay will be held in place by the clip together relay sockets if you’re using them. If not, bolt the other one on at this time. I think where I put mine is optimal when it comes to wire routing. This will ensure you can snip the motor wires and attach them to the relays without adding additional wire to them.
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Find the hot wire coming in, probably the big pink one. Snip this a few inches from the switch plug. See where the ground wire is bolted to the door. You’ll want to solder up a wire (I used black 14ga I had in my parts box) to the pink wire stub left on the switch connector that’s long enough to reach that ground point and apply shrink tubing to it. The other end of this wire gets a ring terminal. Using a terminal with the blue nylon sleeve I crimped it and then soldered, the heat from the soldering tends to shrink the sleeve so that it won’t go anywhere, although it’s also not really needed on a ground. Now attach the ring terminal to the ground point.
You must be registered for see images attach
Next you’ll need to splice the power wire from the cab with the two 12ga wires you installed in the terminal sockets. This will provide power to each relay. I did not trim any from the factory wire but trimmed both of the relay wires down. Strip the insulation off the ends of all three wires and solder them together. Don’t forget to put your heat shrink on first!
You must be registered for see images attach
Finally, take the pair of wires that run from the switch connector and decide where to cut it. You’ll need both ends of the pair to be able to reach your relays. Cut the wires and split and separate the pairs (a few inches will do) on each side. Strip off a bit and crimp on the relay socket terminals, finish with solder and heat shrink. Since these will live in the relay sockets they don’t really need heat shrink but the wires are a bit large for the common terminals. Adding heat shrink will make sure they’re solid and provide a little strain relief. You can go ahead and plug them in to your relay sockets. Each color is for one direction (up or down) and needs to be on the same relay. When the switch is pressed it will connect the ground from the ring terminal we just installed to pin 85 on the relay. This will power the relay, allowing power to flow from the pink hot wire coming from the cab in to the door which is now connected to 30 on the relay, to pin 87 on the relay, which will now be connected to the window motor.
I packed a small amount of dielectric grease in the relay socket terminals - the top side where the relay plugs in. This will keep them from rotting from moisture. You’ve now completed one door. Do the same on the other side and you’re done! Now we’re putting a lot less strain on the electrical system and those windows go up and down at a decent speed. There may be other improvements to be had by working further up the line so to speak, and I will look at that when I get around to doing my LS swap since there will be a lot of rewiring going on then.
You must be registered for see images attach
You must be registered for see images attach
I hope this helps someone and if you see any errors, omissions or room for improvement please say so. I’ll keep an offline copy of this doc and update the post as needed in the future (if possible).
