DDM (Locks/Windows/Mirrors) All of a Sudden Not Working

Skeezix · April 28, 2020

Sorry if this info is elsewhere, I searched but couldn't find anything.

2004 GMC Sierra SLE, 2WD

On Sunday my power module (DDM) on my drivers door just wouldn't work. No Windows, no locks, no mirrors.

The wireless remote still operates the passenger side door but does not lock/unlock the drivers door now.

The module on the passenger door works the lock for the passenger door but not the drivers door. I think it normally operates both.

I looked at the instrument panel fuse for it and changed it anyway, but that wasn't it.

I'm really hoping that it's not the module itself since those aren't inexpensive, starting around $150 or so.

Don't know what else it could be tho.

Also, relatedly, does the cover on the module pop off like it does in the '99-'02 Silverados? My manual says yes, but it doesn't come off easily and there appear to be a dried glue bead around the edges.

Any help would be highly appreciated.

Thanks!

Mark

davester · April 29, 2020

No, the switch DO NOT come out like the earlier GMT800's. If you try to pry the switches up and out, you WILL DAMAGE the interior trim panel and possibly the surround plastic for the switches.

You need to remove the trim panel from the door, then unscrew the switches from the trim panel.

If there's glue around the edges, it wouldn't surprise me if the P.O. pried it out, then glued it in place. Mine had been pried out (both sides, "Maybe they didn't change the other side to match" idiots), and I scoured junkyards for awhile before I found some nice ones (as most people just bust them to get parts in the door instead of taking the 1 minutes to unscrew 3 screws, remove a push pin and lift it off).

Skeezix · April 29, 2020

Thanks a bunch! I was getting that impression.

So when you say trim panel, you mean the interior door panel, right?

Any thoughts on the electric issue?

davester · April 29, 2020

Yes, the whole interior panel covering the door. You pry off the manual lock switch and the plastic cover around the door handle, I believe both pry out from the frontmost side, then unscrew the screw in the lock switch hole, there's another screw in the front upper corner of where the door handle panel was, there MIGHT be another screw in that area, that's easier to see (it's been awhile since I've done it), then the screw at the middle rear of the panel (might have a plastic cover on it that pries off), then a plastic "tree" plug that pulls out the middle front of the panel. Lift up (about 1 inch), then pull outwards (just an inch or two out) to unhook the panel from the door. unplug or remove the door light at the bottom rear of the panel, then you can rotate the the panel and more easily unplug everything going into the switch assembly and the speaker (if you have the option that puts a tweeter in the panel).

Maybe check the door wiring harness, where it passes between the door and the body. It isn't unusual for a wire or two to break from being flexed for such a long time.

The rubber & plastic plug assembly with the harness in it, can be removed from the body as one unit, after you unplug the harness from the truck [remove the trim piece around the hood open latch by first lifting the bottom horizontal part up (just maybe 3/4" to get the clip out), then pull it straight back (towards the rear of the truck)]. The plastic insert (which is covered by the rubber part if it's installed correctly), has two snaps that hold it in place, one at the top and one at the bottom. You can use the edge of a screwdriver to push the top one down a bit, then tilt it out of the body a little, repeat for the bottom one.

If you can't see how to do this, then just peel off the rubber part (it has a lip that just goes over the plastic piece to hold it in place), then you can easily see the latches you have to push down to get the plastic piece out. And, to reassemble, the only way to do it is to first get the rubber part onto the plastic part, then just push the plastic part into the body (I tried for a long time to get the rubber part onto the plastic part with it already in the body, and I couldn't do it, but it's only a couple minutes doing it the other way).

Skeezix · April 29, 2020

Thanks!

I also read somewhere that they need to be programmed, like radios, to fit the truck, is that true do you know?

That doesn't seem logical.

Mark

davester · April 30, 2020

I don't know if the driver door module needs programming or not. I've swapped in one from a junkyard in my truck, with the exact same switches, and it just worked.