Door locks gone mad!!!

[blazer_guy86]

Got a 98 4 door here with electric door locks and remote keyless entry. Goin down the road today (in the rain) and door locks start locking and unlocking by themselves. So i got home and started checking fuses and such and found nothing. The switches do nothing. At first i couldn't get the back glass to open neither with the remote nor the button on dash. I can hear the relay making noises in the dash but nothing happens. Now is seems as there is someone pushing the back-hatch button non-stop cause you can hear it so now it will not close.So i take the battery out of my remote thinking it might be messed up. Nothing. Disconnect battery for half hour connect back, same thing.

I've read simular threads but can't find much except for water might have something to do with it. Thanx.

[berniescout]

had a similar problem 2 yrs ago after going throught deep water after a heavy rain. let it dry out. at the time i was also having a problem w the drivers electric seat not working. found dead short in seat where the steel fram had rubbed through 4 or 5 wires under the seat padding. i have a post in this forum about it. ifi remember correctly the locks and the seat are on the same circuit breaker, not a fuse, inthe 97 blazer, which i have. since fixing the seat the door lock problem disappeared,

[blazer_guy86]

Power seats are functioning normal. I checked all wires and all seem to be good. I manually locked all doors last night just to find them all unlocked this morning. I can hit the lock button and i can hear the relay but no movement. I can hit the unlock button and nothing happens. I'm stumpted here. Luckily i do own another 98 blazer so i'll start interchanging door lock switches and such to see if i can track down the problem.

[Chris Stewart]

Disconnect the blue/black wire connector under the rear of the passenger side front seat (and going up into the seat back) and retest...my lumbar support wiring has an intermittent short on my '97 but still operated and caused the same problem as yours. Disconnecting it stopped the haunted doorlocks.

[blazer_guy86]

I found the wire connector and disconnected it. Still the same. Just for the record, only my driver seat is power and it only moves up down forward and backward. the lumbar and lean-back is manual. I also put in a different lock/unlock switch from my other blazer. Still the same thing. Running out of ideas here. Thanx Chris Stewart for trying to help. Any more ideas are appreciated.

[Chris Stewart]

The interior lights are in that circuit too('97). Are they ok? Since the interior lights, power seats and PDL's are in the same module, any intermittent shorts to ground in any of them causes everything else to act up. Check for gum foil or pennies in your cigar lighters and power supplys.
The seat wiring passes under the carpet under the drivers feet, feel for heat or pound lightly with the side of your fist to test for door lock haints.

[berniescout]

i forgot the interior lights are on the same circuit. there are two sets of pllugs under the drivers seat. unplug both and see if the problem goes away

[blazer_guy86]

Ok, moved some wires around and accomplishes nothing. Unpluged both wire connectors under driver seat and nothing. All interior lights are working fine. I can pull the fuse to the power door locks in fuse panel and manually lock the door and put the fuse back in and doors unlock by themselves. It's as if there is an unlock button being held down somewhere. So then i disconnect both (driver and passenger) door lock switches, pull the fuse, manually lock the door, put fuse back in and doors unlock. So at this point i close door and walk away and door locks go crazy again with random locks and unlocks so i go back and move some more wires and accomplish nothing.

[Chris Stewart]

Try this reprogram with your remote to see if it'll help,

ZL1power69 wrote:

welcome to af. if the truck came with keyless entry (u can see the module under the drivers side dash), just get a replacement remote on ebay (search 2000 blazer and you should have no problem finding one). to program the remote(s), i believe you hold down the unlock button on the door, turn the key on off on off, then hold the lock and unlock buttons on the remote(s), then turn the key on to exit programing mode. im pretty sure thats it.
Thanks ZL1power69

[AJT1961]

I doubt this will be much help, but I nevertheless will share my limited experience with door locks gone wild. I had this problem once on my 99 Chevy Venture while driving down I-95 near the NC/SC border on a vacation from Philly to FL. The door locks went absolutely berserk for about 20 miles and then stopped. Never happened again until about a year later when I was driving along the very same stretch of I-95 on vacation again. I don't know much about the electronics of these wireless systems but I will always be convinced that it was caused by some weird/lucky combination of radio transmissions in that particular area. Or it was just a one in a million coincidence, but in 140,000 miles of driving that was the only 2 times it happened, and I had only driven that stretch of I-95 4 times.

[blazer_guy86]

That's crazy. I go outside this morning and everything is working normal. Lock unlock and rear window except about every fifth time i hit unlock the rear window opens. I looked behind the panel where the relay is spose to be but couldn't find it. All i found was the box for the keyless entry system. Can anyone tell me more of where the relay is located? I'm gonna replace that and see if that does the trick.

[Chris Stewart]

In the fuse panel, the upper breaker is primary juice to the door locks and fuse #2, top row , 2nd from the left, is the fuse to the door locks.
This is a "Hot at all times" circuit, it'll be hot even with the keyswitch off.
If your power seats work, the breaker is OK...onna '97
The Power Door Relay looks to be behind the glove box with 5 wires,
white, orange, light blue, tan and gray.

[blazer_guy86]

Problem solved! Replaced lock and switch for back glass. Old one was shorting out and everything is working normal now. Thanx for everyone's help.

[Chris Stewart]

Hooray!!! Gotta try to remember this.