More Door Lock Electrical Issues

[BuffaloXplorer]

Well, for about 1 1/2 years i haven't been able to lock my X with the keyfob, keypad or the front door locks. The rear tailgate switch works fine, though.
(I think) i know where the problem is but haven't had the time (or taken the initiative) to fix this issue.

Now, the doors will no longer UNLOCK with the keyfob or the "double-turn" of the key in the lock cylinder - BUT the keypad still unlocks the doors.

I DO have an aftermarket remote-start/keyless entry unit installed, and neither the OEM nor the aftermarket keyfobs will perform this function.

Any ideas on what/where to check? I don't know a thing about how the remote start is wired, but i'd like to know if anything they did screwed up my lock system.

Is there any way that the GEM is involved/faulty?

 

[budwich]

The lock and unlock power and switch paths are different. That is why one can work while the other doesn't and vise versa. Depending on how they install your after market keyless, they might have caused your problem.... either by coupling onto a wire with a "punch coupler" which cuts thru the insulation and "scissors" the wire to make a connection.... if they didn't use the right size, then the "scissor action" might have weaken or cut thru the wire. If they used crimp connectors, a crimp may have given out. Lots of possibilities. Anyways, I installed a bulldog security keyless unit a couple of weeks ago on my 96 and use the access provided in the left side cargo compartment. The door relays are there so access is easy and quick. Maybe they did their work there. I don't believe GEM plays a major role... it is usually a wiring problem. For the FOB stuff, the RAP module is involved.... which is also in the same compartment.

PK/Y wiring delivers "lock control" while PK/LG delivers "unlock control". BK is gnd while BK/W is hot at all times. I can't help with the remote start as my unit doesn't do that. I can probably help more but you need to do more isolation of exactly what working and what is not (ie. what switches, or remotes cause something to happen, and as many permutations there of). Of course, there is a fuse (#5) in the power distribution box that powers all the door stuff among other things. Good luck and take the time to poke around.

 

[mykalhenry]

I have the same sort of problem on a 01 Sport. The key fob is still stock. Nothing unlocks the doors but the key. When in the truck and I lock it manually, the only way to get out is to pull the handle. Both doors work the same and the master power lock and the passenger power lock yield the same results as the keyfob. If locks are down I hear a clicking and the lock shudders but will not move up. Same if up, you hear a click and the locks move around a bit but not down. The hatch in the back yields the same sound when I try the fob and am in that area of the truck... The key opens and locks everything though.

What do you think the course of action should be?

Thanks,

Mykal

 

[budwich]

Mykal, I think you have a slightly different problem than Chris... although you have qualified yours more with the "sound bytes"... ... I can't tell from Chris's details whether the lock attempt to work or not.

Anyways, your probably best course of action, is to take the entry that is easiest to get at (ie. I find the tail gate is pretty good but it depends.... its also easier to see into the channel to find out what's going on... JMO). Before you get started though, make sure you confirm your observations that all locks operate or attempt to operate the same way. If not, then you need to check the one that is different. If they are operating the same, I would find it hard to believe that they are all mechnically "broke". Hence, it is more likely an electrical problem. You are probably going to need a multimeter. You will likely need to measure your battery to grd voltage with nothing on / open. Then again, with whatever entry point you have open just so you can see what a "good" reference voltage is. At the entry lock motor for the port you are going to check, there are two leads, PK/O & PK/BK. Measure the voltage you see at one of them to a "known good ground" while someone hits the lock switch at the door or tailgate. Repeat for the other. One should read close to you battery voltage while the other should read "0" (grd). Repeat the test but now hit the unlock switch. The readings should be reverse (ie. the one that was "0" should now be "battery", etc). Compare the voltages, they should be the same or very close. If the "voltage" is close to that of the battery then it is possible that you have a ground problem (ie. poor grd) and hence not enough "oomph" to cause the motor to react fully. If the voltage is a lot less, then it is likely you have a bad "hot" connection along the way to the door lock relay (not the motor). Having said this, both grd and hot are switched at door lock / unlock relays and therefore, it is possible that the door lock relays (contacts) are poor resulting in bad connections thru them. As mentioned in the earlier post, the door relays are in the left cargo compartment with access thru the jack panel (at least in 96). If you can measure voltages at these relays and compare those that you see at the lock motors. Lastly, even though the key lock and unlocks everything, try and see if you can get inside the door / tail gate panels and lubrication things a bit... it can't hurt. One Last thing, you can try and unplug all but one lock motor and see if this helps things. Be very careful though, the plastic plugs / snap locks break very easy and then you will be having a problem keeping / putting them back and keeping them back. That's what happening to my driver's side and why I played around with the lock schematics... my driver side door wasn't working... ultimately, I had to tape on the connector and hope it holds. Good luck in your "chase". It is most likely that your problem is around the door lock relays.

 

[BuffaloXplorer]

Thanks Bud - FWIW, the keyless module is beneath the dash - it is kinda stuffed in there, so i'd bet (hope) that a wire or two have come undone. I may get a chance sometime this week to get under there and look, but i've said that about other things too (see lock problem). In that thread i've got very detailed directions and most likely a fix - I'm just reluctant to start ripping apart bundles of wire to find a P/Y, et. al. Actually, i'm definitely going to take the time to look into the aftermarket remote start unit b/c i need to open up the dash to change a few bulbs, too.

I'm going to start small and clean the master switch, because i DO have an issue with the window lock not always working and the right-rear window will not move. I'm not expecting that to fix the lock issue, but i do have other electrical demons that need to be exorcised, too.

How does the rear/side interior trim panel come off, so that i can get a good look at the RAP & relays?

 

[budwich]

You don't have to take the rear trim panel off... the left side has the tire jack compartment which comes off with a couple of latches. You will see the relays and RAP from there.... at least on my 96 XL.

 

[BuffaloXplorer]

I've been in there - it's tight! Access isn't optimal through just the jack panel. I really need to trace this P/Y wire from the relay all the way to the 2-way split just in front of the rear seats (goes to both front door lock switches, i believe)