power lock problems

i installed power locks in my 92 ls. I used 92 gs doors and lock control unit. the problem i m having is that the drivers side door will unlock, but not lock. the pass door will not do anything. I can t figure it out. i need help bad.

Well it has to be one of two things, the system is defective or you miswired something.

The first thing to do is test the actuators, the pass. door actuator has 2 wires, should be yellow/red and white/red, supply 12V+ to one of the wires and ground to the other, actuator will lock or unlock, [depending on polarity] if it works, switch the power and ground and actuator will move in opposite direction, if that works the actuator is good.

Now do the same with the drivers door actuator, it will have 4 wires, should be, black and blue/white, [they are switch wires for central locking and not used for testing] the ones you need for the test are black/red and yellow/red or another black/red, do the same test as the pass. door actuator.

If you have the actuators wired properly to the “Power Door Lock Control Unit” you can do the test there, for both actuators, use the yellow/red and white/red leads, if both actuators “lock and unlock” from there the actuators are both good and have been wired correctly up to the “PDLCU”

Do the tests and let , me know what happens.:hmm:94

thanks alot! i will check that out and get back to you.

i tested both sides and nothing happened. then i tested the plug thats goes into each door, no power to the yell/red or white/red wires.

What do you mean, “then i tested the plug thats goes into each door, no power to the yell/red or white/red wires” how did you test them, what were you testing for, power?

The power door lock system in a G2 is a “Ground At Rest Polarity Reversing System” meaning when at rest, [not being locked or unlocked] both the wires going to the actuators are grounds, so if you test the yellow/red and white/red they should both read as grounds, when you lock the doors the white/red will go to 12V+ for just under 1 sec. when you unlock the yellow/red will go to 12V+

You said you used doors from a GS and the lock control unit from the GS, is that correct?
If so, how did you wire the door lock module, as the LS is not wired into the doors for power door locks, if you used the GS doors the door harness will have all the wiring but where it plugs into the dash harness the door lock wiring is not there.

Test these wires at the module…

1- White/yellow, should be 12V+, [hot at all times].
2- Black, should be ground.
3- Black/white, ground when unlocking pass. switch.
4- Black/red, ground when locking pass. switch.
5- Green/red, ground when unlocking drivers switch.
6- Green/white, ground when locking drivers switch

and again, the white/red and yellow/red should both test as ground, [at rest] and white/red will go to 12V+ when locking and the yellow/red will go to 12V+ when unlocking

The blue/white lead is off the switch in the drivers actuator and will read as open when doors are unlocked, and will go to ground when doors are locked, even if you use the key or manual lock lever, [central locking].

You do have a multimeter to check the above, right?

You may have to pull the door panels so you can check the wires going to the actuators themselves.:whisper:94

i tested both actuators, they unlock but dont lock.

That is very unusual, that they would work in one direction and not the other, where and how, are you doing the testing?

It is possible that they have a “dead spot” at one end of their travel.
Try this, once you have unlocked them and after you reverse the power and ground push the actuator in a little, just enough so it is not at the end of its travel.

An actuator is nothing more then a motor with a pinion gear on the end of it’s shaft that drives a rack, [actuator rod/shaft] when polarity is in one direction, [power on one wire and ground on the other] motor turns in one direction, when you reverse the polarity, [switch the power and ground] the motor turns in the other direction, so if it works in one direction it should work in the other direction, as I said it is very unusual that the work one way and not the other, even more so that both have the same very rare problem.:hmm:94

finally got both doors to lock. the weird thing is know, they will not lock or unlock with the doors closed.

You definitely have something miswired or a connection problem.:stare:

As you seem unwilling to answer the questions I ask or confirm that you have done the tests I suggest there is not much I can do to help you.:tapfing:94

when i did all your test, i found out i had the two door plugs on the wrong doors. i unhooked all the wiring and switched the plugs. everything seemed to work finally till i closed the doors. then nothing.

Then I would check the connections of the plugs in the door to dash harnesses.:stare:

Do they work again if you open the door(s):hmm: 94

yeah they will work every time you open the doors, but when you shut them nothing. i will diffently recheck the connections.

finally got everything working. thanks fo all the help.

:clap: so what was it???:hmm:94

it was a loose ground wire at the pass. side door plug.