Power Window Wiring

[playinsafe44]

I just got some full power doors off of an '87 blazer, but I don't know the best route to do the wiring. I also pulled the wiring out of the blazer to put in my truck (with the relay). I just don't know what is hot, ground, constant, or switched... This is going on my '73 Chevy, so it has the buss (bulb) type fuse block on it. I also read somewhere the there is a relay mod that can be done to make the windows work better, and I would rather install it that way if I can. Thanks!

[playinsafe44]

Anyone? To get started, I just need to know where the three wires go (red clip, black clip, and blue clip).

[STOCKISH]

They would plug into the fuse box. I dont have power windows in my truck yet but hopefully someone will be able to help. Anyone out there with power accessories that can give this guy a hand???

[joe231]

black is ground
red is all time 12VDC
blue is switched 12VDC

[Alias137]

Those red, blue and black clipped wires plug into the newer years fuse blocks. I don't know the specific year that it was changed, but that is where they go. There are specific terminals for them on the newer blocks. I got one (for free-well almost free- you pay for shipping) if you want it. Pm me if you do.

[68 TT]

Your fuse box doesn't have the stock spots for them to plug into since it is pre-77 when it became an option but you can put the older glass fuse type terminal ends onto the pink, black & orange wires so they can plug into spots on your older fuse panel that were meant for accessories if there are any with a high enough amp rating.

You will need a fused power source that is constant on and one that is ignition on hot for the pink & orange wires and the black one can be grounded to the body under the dash with the other grounds to the left of the speedo. If I remember right the pink is the constant on power and the orange is ignition on hot.

The large plugs connect to the door component connectors where they come through the kick panel from the door.

[playinsafe44]

Thanks for all the great info! I really don't want to change out the fuse panel if I don't have to (I don't see the benefit). I figure that as long as they are wired in correctly it should be fine. I already know that I will probably have to change the connectors for where it originally plugged into the panel. Now is there anything else I should know? The plan is to put an inline fuse on the two wires that have power to them, I just don't know what rating of fuse to go with (20 amp?). Would it be better to do the mysterious "relay mod" from the get go?

[68 TT]

I am guessing the relay mod is just a 30-amp fan relay and having it ignition on hot for the window motors to get full battery voltage instead of reduced voltage as you get through the fuse panel.

[joe231]

Pink is switched power
orange is constant hot as I stated previously.
I believe the constant hot is fed through a 30 amp breaker on the correct fuse box. I'll have to look to see what size fuse is inline with the switched power.

[playinsafe44]

Can I wire in a 30 amp breaker without using the spade style fuse block?

[FLEET72]

This may help. or not.


Larger version here: Part 1 Part 2

[FLEET72]

Originally Posted by playinsafe44

Can I wire in a 30 amp breaker without using the spade style fuse block?

Yes. I would use a 30A Bosch style relay
and an ATO style Circuit Breaker

Connect one side of the circuit breaker to the battery or or distribution point that is supplied by a heavy wire. The other side connect to terminal 30 of the relay. Terminal 87 will connect to the pink wire of the power window harness. The Orange wire of the harness is not used for the power windows but supplies the power door locks.

Connect terminal 86 of the relay to ground and 85 to a Ign/Acc source. (there should be a terminal on your stock fuse box you can use)




See a similar setup here.

[playinsafe44]

Sorry if I missed it, I just want to make sure I get this right and so I don't cause a fire or something haha. I only need one circuit breaker, and one 4 pin 30Amp relay? I read that the pink wire would plug into the relay, but what about the other two (black and orange)? Would I just plug the orange into a regular constant hot with a fuse, and ground the black anywhere? I really appreciate all this help!

[STOCKISH]

Thats what I'm getting from it. Let us know how it works out for ya.

[FLEET72]

Originally Posted by playinsafe44

Sorry if I missed it, I just want to make sure I get this right and so I don't cause a fire or something haha. I only need one circuit breaker, and one 4 pin 30Amp relay? I read that the pink wire would plug into the relay, but what about the other two (black and orange)? Would I just plug the orange into a regular constant hot with a fuse, and ground the black anywhere? I really appreciate all this help!

You will need to connect the orange/black wire to a 30A circuit breaker as well. This one won't need a relay.

On second thought, you could use just one breaker and connect the orange wire to it before the relay. I doubt you would be rolling up both windows and locking the doors at the same time.


The black wire to a good ground. You may want to use this type of breaker instead of what I posted earlier, makes for easier mounting:


And here is the door lock diagram:


And the bigger version; part 1 and part 2.

[joe231]

Everything that I'm stating is the factory wiring

The black is chassis ground.
The orange wire is all time hot for the locks and is protected by a 30 amp breaker.
The pink is switched power for the windows so they will only work with the key on and they are protected by a fuse (not sure what amp rating)

the relay must be wired into the window circuit (power wires to the window motor) to see any benefit.
The link posted above (and the info in the post) is a relay mod for headlights and won't work for the windows.
You want to use the window switch to energize the relay to supply full battery voltage to the window motors.
If I were you I would get the power windows and locks installed first. Then once you have them in and working you can do the relay mod. Right now it seems to be confusing the issue.
In the mean time I will try to find the diagram for the mod, or try to find time to draw one up for you.

[FLEET72]

Originally Posted by joe231

Everything that I'm stating is the factory wiring

The black is chassis ground.
The orange wire is all time hot for the locks and is protected by a 30 amp breaker.
The pink is switched power for the windows so they will only work with the key on and they are protected by a fuse (not sure what amp rating)

the relay must be wired into the window circuit (power wires to the window motor) to see any benefit.
The link posted above (and the info in the post) is a relay mod for headlights and won't work for the windows.
You want to use the window switch to energize the relay to supply full battery voltage to the window motors.
If I were you I would get the power windows and locks installed first. Then once you have them in and working you can do the relay mod. Right now it seems to be confusing the issue.
In the mean time I will try to find the diagram for the mod, or try to find time to draw one up for you.

First, Yes, black is ground, orange is always hot and pink is switched ign.

Second, NO. The use of a relay is only so that you do not overload the stock '73 fuse block. The stock wiring in the '87 doors is sufficient to handle the draw of the power window motors so no need to change that. The factory wiring diagram for the 87 lists the power windows protected by a 30A circuit breaker and wired with 12ga. wire.
Here is a picture of a 72 fuseblock, the layout is similar to the 73. It does not have any fuses larger than 25A, I would not load it with the draw of power windows hence the use of a relay and circuit breaker.


A relay is a remotely controlled switch that that can handle more current than the primary circuit. This is not a "mod" just proper application of an electrical device.

Imagine in the drawing of the lights, that you substitute the power window complete circuit for the lights themselves. I suppose I should draw it instead of being lazy and using someone else's work, albeit much prettier.



I hope this makes it clearer, if not ask away, I'll try harder.

[joe231]

Here is some info

http://67-72chevytrucks.com/vboard/s...d.php?t=243042

[joe231]

In the headlight relay mod, the relay is there to provide full battery voltage to the headlights without routing it through the headlight switch, which accomplishes brighter lights. It is the same for the window motors. You use the window switch to energize the relay to provide full battery power, which results in faster window operation. It has nothing to do with the wire size in the doors.
What you are referring to is practical, but it is not the window relay mod that the OP was asking about.
So it seems to me you and I are discussing apples and oranges

[FLEET72]

Originally Posted by joe231

In the headlight relay mod, the relay is there to provide full battery voltage to the headlights without routing it through the headlight switch, which accomplishes brighter lights. It is the same for the window motors. You use the window switch to energize the relay to provide full battery power, which results in faster window operation. It has nothing to do with the wire size in the doors.
What you are referring to is practical, but it is not the window relay mod that the OP was asking about.
So it seems to me you and I are discussing apples and oranges

Yes, apples and oranges. And they both have seeds. The reason for the relay here is because the 73 fuseblock cannot handle the current draw generated by the power windows (in theory). The reason I suggested it is to protect the stock wire harness.


I guess I missed that mod question in the op. I don't see a "relay mod" helping in power windows because they came from the factory wired with 12ga. wire which is rated to 41A @150*C. There is minimal resistance there unlike headlights wired with 18ga. from the factory which are only good for 16A. The mod has everything to do with wire size, smaller wires resist current flow resulting in reduced voltage. That's why the mod includes using bigger wire for shorter runs = less resistance = less voltage drop. In my mind it would be better to ensure good connections throughout the system and/or just replace tired motors.

Of course this is IMHO and YMMV.

[joe231]

my plan is to replace brushes and clean the commutator.
I've cleaned the commutator on one of my extra motors and it seemed to have made a difference that is noticable while bench testing.
I'm also thinking a higher amp alternator couldn't hurt.

[FLEET72]

Originally Posted by joe231

my plan is to replace brushes and clean the commutator.
I've cleaned the commutator on one of my extra motors and it seemed to have made a difference that is noticable while bench testing.
I'm also thinking a higher amp alternator couldn't hurt.

Electric motors do like to be clean, too bad we put them into some of the harshest conditions possible. And considering they are 20 -30 years old, I'm amazed they work at all sometimes.

[68 TT]

For the relay mod to boost window motor speed the power needs to come straight from the battery and not from a source on the fuse panel so it gets maximum voltage.

You could also wire in a delay circuit so the relay stayed on for a while after the ignition was turned off like some newer cars have that way you can still roll up the windows after the key is off for a short time.

[68 TT]

I just found a diagram for delayed accessory power that will work easily for keeping power to the radio and the power windows until a door is opened and it just uses typical inexpensive Bosch relays.

I cropped out just the part I was interested in on the PDF since there was a bunch of other stuff on the page but left the link to the whole article at the top of the attached PDF for proper credit and more info if you want it.

[playinsafe44]

Ok, so we are talking about two different uses for the relays. I'm going to go ahead and install the wiring using the single relay mod as shown in Fleet72's little sketch up. I don't expect this to make the windows perform any better than the stock setup, but it will make for a clean and easy install. The other relay mod would be to install 2 relays per door, one for up and one for down. This would take the load of of the switches, reduce the voltage drop, extend the life of the switches, and hopefully speed up the windows by providing full voltage to the motors.

I'm going to get the doors installed with the one relay for the harness just to get started. Once they are in I plan on tearing the doors apart to clean the tracks, rollers, insides of the motors and switches. I also picked up some garage door spray lubricant to slick everything up. Once I'm this far, I want to try the relay mod to speed things up (2 per door). I found this diagram that looks like it should do the trick. Let me know what you guys think. http://www.thestreetrodstore.com/Doc...icWindows1.pdf