I bought a 99 sedan not too long ago and noticed that the driver lock is acting funny.
It won't lock or unlock with the remote, but the rest of the doors will, as long as I unlock the driver's door manually first.
With the switch on the door, it unlocks the rest of the doors, but it won't lock them at all, I don't even hear them attempting to lock.
The rest of the doors DO lock when I manually lock the driver's door.

After some searching I figured I should replace the actuator. Just finished doing that and still the same problem. Anything else I should try?

 

With a multimeter, check whether the Blu/Red wire that runs between the driver's door lock actuator and the keyless lock control unit (behind driver's kick panel) has an open or short.

 

Alright cool, pretty sure we have one somewhere in the house, I'll find it in the morning. What voltage should it be at with the car off?

 

The open and short tests are resistance (Ohm) measurements (not voltage measurements) for end-to-end continuity or continuity to body ground, respectively.

 

Ah, so I just picked up a multimeter, have no experience using it. I found the red/blue wire in the plug plugged into the keyless control unit, should I poke it with the red lead and stick the black lead on a ground?

 

same problem here, maybe yall could help me out too. sorry, kinda jack your thread. lol

 

It's all good. I just did what I said there and got .7 - .8 ohms with the car off.

 

This^ means there is a short in the wire. Now do the same test on the Red/Blu wire but first unplug the driver's door lock actuator and the keyless control unit.

 

You mean the plug right into the white box right, not the one in the door? Let me try it.

 

Unplug both connectors (control unit and actuator) and then redo the test.

 

By just unplugging that 1 plug I said the multimeter stays at 1.
I haven't unplugged the other one because taking the door panel off takes a few minutes and it's blazing out there..

 

When it's cooler:

Do the same test for a short at the unplugged actuator connector.

Next test the Red/Blu wire for an open. This is done by measuring the resistance of the Red/Blu wire from its terminal in the actuator connector to the same terminal in the keyless control unit connector.

 

Alright, parked in some shade

I'm not sure if I really understand. So I'm gonna do the same thing, but on the new actuator's plug? Should I put the red lead right into the plug or stick it into a wire?

Then for the red/blue wire, I don't understand where to put the leads from the multimeter..
"the Red/Blu wire from its terminal in actuator plug to the terminal in the control unit plug"
As in put the red one into one side of the red/blue cable and the black one into the other end of it?

 

To test for a short, put one lead (doesn't matter which) into the plug on the terminal for Red/Blu wire and then ground the other lead to the metal frame under the dash.

To test for a wire open (broken wire), put one lead on the Red/Blu wire terminal in the control unit connector and put the other lead on the Red/Blu wire terminal in the actuator connector. What is the resistance (Ohm) reading?

 

On the first test it stayed at 1. and on the second test it settled at .8

 

I've been writing Red/Blu wire for the last few posts but I should have been writing Blu/Red wire. As there's no Red/Blu wire in those two connectors, can I presume that you actually did the tests on the Blu/Red wire? If so, the Blu/Red wire is fine.

Now do the same test for an open but do it on the Wht/Red wire (measure resistance of the Wht/Red wire between control unit and actuator connectors). What is the reading?

 

Haha yea, I've been using the blue/red.

Assuming I'm doing it right (simply putting a lead on either side of the white/red wire), it's staying at 1.

 

Do the wire open test -- a lead on both connectors.

 

Isn't that the same thing? It's staying at 1

 

Your use of "either" rather than "both" here gives me the impression that you tested one terminal for a short rather than both terminals for an open. Stating results precisely and unambiguously is crucial when relaying technical information.

If you properly tested for an open, then you found it.

 

Haha no then it should say both. So how should i go about fixing this? Thanks for the patience..

 

A very common location for a wire break is where the wire harness passes from the cabin into the door, due to constant flexing of the harness there. Look there first.

Otherwise you can use a more methodical approach of probing for loss of continuity at various accessible points along the wire.

Once the break is found,repair by splicing, soldering, and shrink wrapping.

 

By the way, connector C556 is situated between the lock control unit and the driver's door lock actuator. The Wht/Red wire passes through C556 at terminal 12. Doing continuity tests (for an open) on both sides of C556 will pinpoint the wire break to the lock control unit side versus lock actuator side of C556.

 

Did anyone solve the problem