Greg Smith Power door locks writeup PRE-1991

[andysmith89XJ]

Originally Posted by wgregt

Look at page one of this thread. Greg's write up is there.

I was referring to the power window* modification. It seems easy just trying to find pictures or steps on how to do it. Any concerns of overloading the exisiting wires by going straight to the battery?

[tjmotter]

Originally Posted by andysmith89XJ

I was referring to the power window* modification. It seems easy just trying to find pictures or steps on how to do it. Any concerns of overloading the exisiting wires by going straight to the battery?

Here is how I wire it for both the door locks as well as the windows.



I found it MUCH easier to just tap into the wires in the door rather than directly connecting the wires to the battery. The issue is that you need a set in each door and squeezing new wires through that loom is a bit of a PITA.

For the ground, just solder the two wires together and crimp or solder a ring connector like the one in the link below. Use an appropriately sized pair of bolts/nuts and connect the relays and this ground to one of the holes where the manual crank would sit. To ensure a good ground, I sanded a bit of the paint off on the interior side of the mounting point so that the bolt head would make a solid electrical ground. For door locks, simply mount it to the frame somewhere.

https://www.belmetric.com/index.php?main_page=product_info&products_id=1349& cPath=19_164_202_2390&msclkid=e3bf4dd78f771d82498b 12688f9f32fc&utm_source=bing&utm_medium=cpc&utm_ca mpaign=%2A%2ALP%20Shopping%20US%20-%20Electrical&utm_term=4584001421561164&utm_conten t=1349%20%7C%20E901%20-%20Uninsulated%20Ring%20Terminal%20%7C%20%241.65&z enid=do6fmatve9mjn8hhdv198au805


For power to the windows, I simply grafted the power wire to the Violet/White strip wire going to the switch. This provides 12V when the ignition is on and is protected on the fuse panel. The power going to this wire is more than enough for the windows. For power to the door locks, you can route the wire to the battery since you will be placing the relays behind the kickplate.

To tap into an existing cable, something like this works best:
https://www.walmart.com/ip/30-Pairs-...7c49365bf9e27e

The inputs will be the wires coming from the existing door switch.

The outputs will go to the window motor or the lock depending on which you are installing.

Unless you have a meter and want to scope the power flow before you start there isn't an easy way to determine the input/output wiring. There are only 2 possible combinations so the easiest way I have found is to wire the inputs permanently (coming from the switch) first. Next, connect the outputs temporarily and test the system. If you press the lock button down and it opens, reverse the output wires. Same with the window circuit. If you press down and the window goes up, reverse the output wires and it should work properly.

The "theory of operation" is pretty simple.

Using a 5 post relay, the default position will connect Pin 30 to Pin 87a. When power is applied to pin 86 of either relay, it will switch that relay so that Pin 30 connects to Pin 87.

The pins marked 85 and 86 are the two sides of an electromagnet. Since pin 85 is connected to ground, simply applying power to pin 86 (when you press the door switch), will turn that relay on. The door switch is designed so that when you press "down", one of the output wires connects to ground and the other connect to 12V. When you add these two relays, the wire that goes to ground stays "low" which means Pin 30 is connected to Pin 87a which is already tied to ground so that relay will stay off but the relay will provide a ground path for the motor. The wire that connects to 12V turns the second relay on which connects the motor directly to the 12V power line that feeds the switch. When you press "up", the order is reversed so the first relay goes to 12V and the second relay stays connected to ground.


HTH
Todd

[Phil]

Thanks for the diagram. So you are saying, there is legit 12v power already run to the door that is just not being used well?

[tjmotter]

Originally Posted by Phil

Thanks for the diagram. So you are saying, there is legit 12v power already run to the door that is just not being used well?

Correct. The violet wire with the white stripe has more than enough power to drive the windows. The issue with these older Jeeps seems to be that this power cannot transmit through the switch as well as when they were new. When you wire it this way you are actually using the circuit the way the designers intended. The only difference is that the switch no longer has to provide the high current, the relay does this. This also means that the circuit breaker that Jeep installed in your fuse box is still protecting the entire circuit. There is a very small incremental load on the violet/white wire since it is also used to trigger the relay but this is too small to matter.


HTH
Todd

[andysmith89XJ]

So are you saying there will be two relays in each door panel for the window modification?

[tjmotter]

Originally Posted by andysmith89XJ

So are you saying there will be two relays in each door panel for the window modification?

Yes. Also, I would strongly recommend using weatherproof relays since this area has to deal with water that seeps past the window seals (which is why there are drain holes at the bottom of the door).

[Taghard]

Good evening, I’m new to this site. I have been working on getting my locks working for days. I have the relays wired just like it says. I have read and reread, gone over multiple times. I simply cannot get them to work. I get the relays to click, but no lock movement. Now if I put a ground one of the wires the lock open/ close depending on the tan or green that’s grounded. Remove the ground and put it on the other one and the lock works. After that the relays just click.

1988 Jeep Cherokee

[justdigit]

Originally Posted by Taghard

Good evening, I’m new to this site. I have been working on getting my locks working for days. I have the relays wired just like it says. I have read and reread, gone over multiple times. I simply cannot get them to work. I get the relays to click, but no lock movement. Now if I put a ground one of the wires the lock open/ close depending on the tan or green that’s grounded. Remove the ground and put it on the other one and the lock works. After that the relays just click.

1988 Jeep Cherokee

I was very thrilled when i found this thread. And it's sort of alive.

Did you solved your issue?? I have the symptoms as you have.
When I disconnect one wire from the door side the locks work but when all wires are attached to the relais they only. clicks.

[Phil]

I’ve had this link saved for a while and might or might not try in the next couple days on my 1989. I had the door panel off to play with the power window this afternoon and man, it is tight trying to work in there.

[cruiser54]

I've done 2 or 3 of the upgrades. Sure works well.
It's tight in there and the instructions are a bit of a brain teaser.