More door lock issues

arctictraveller · 05-27-2019, 11:02 AM

So, my new van has caught the same virus my old van had. (Perhaps I shouldn’t park them so close together?) Anyway, a couple years ago, while driving down the road, suddenly the door locks began locking and unlocking all by themselves. A couple of times I returned to my formally locked van to find the doors unlocked. This continued for a week or so, and then went away all by it’s self only to return another time for a short while. Yesterday, while installing new carpet, the same thing happened on my new van while sitting in the driveway, the locks suddenly began locking and unlocking with no input from me. Prior to this, they didn’t work at all. What I lack is an accurate understanding on how this system works. Both vans have the keyless entry module. As best as I can tell, each door lock motor has power on both sides of the circuit (12v +) until the master switch on the drivers door or any other switch is actuated to lock or unlock, at which time one side or the other goes to ground through the switch to actuate the lock solenoid. If any switch has bad contacts, it affects the entire system. Supposedly, its not uncommon for a wire to short to within the flexible rubber tube that goes into the doors, since they flex every time the door is moved. This condition seems to be quite common, since a quick search here and on Google finds lots of advice on how to troubleshoot, and often times it’s blamed on the KEM, a part no longer available from Ford. I have the factory manuals, and have done the recommended pinpoint tests in the manual, with no faults found. So, can anyone confirm my understanding of how this system works?

Twoxentrix · 05-27-2019, 01:14 PM

I had the same symptoms develop a while back. Initially I blamed the Viper Alarm system, and had the installer disconnect the unit - I was wrong since the locks still had gremlins controlling them. Read much info from others which had similar experiences, providing a lot of speculation on where to look & probable causes...when I came across someone suggestion that it may have to do with low voltage. At the time I already suspected my batteries were nearing end of life (confirmed when tested) - soon as I replaced batteries it all went away - no issue since. More than likely I just got lucky.

1der · 05-27-2019, 01:48 PM

Pull your driver side B Pillar cover and the paneling to get access to the wire harness that runs up from the floor. Check that harness top to bottom very carefully for rub through and shorting.

When SMB makes the cut for the side window they leave very ragged unprotected edges. Just helped another member repair 5 wires that had started shorting along that harness.

Hopefully there is not a screw that has compromised the wire harness running along the driverside upper behind all the cabinets.

arctictraveller · 05-27-2019, 06:14 PM

Quote:

Originally Posted by 1der

Check that harness top to bottom very carefully for rub through and shorting. When SMB makes the cut for the side window they leave very ragged unprotected edges. .

Thanks Ray, I'm aware of the issue, since that's what nearly caused Ramseys van to catchy fire down in Baja. I'll check the harness as best as I can, but it's mostly covered by paneling captured behind the refer cabinet. Never the less, good news.............Suddenly all the lock switches and the alarm remote are working normally, with no repairs from me. I suppose it's possible the batteries were low, since I put a charger on them last night due to the continued actuation of the locks, but I can't say for sure they were low as the volt meter showed a reasonable charge. So, once again the door lock gremlins strike and then depart with no clues as to what they are doing. I can only hope they stay away.

JWA · 05-28-2019, 07:43 AM

AT what year is your van and does it have the Ford Remote Keyless Entry (RKE) option installed?

86Scotty · 05-28-2019, 08:17 AM

Have you pulled your rear right side door panel off? Another thing I've heard of is that on 2000 or so and newer vans the original door panel has a door lock switch in it and when SMB (or any converter) replaces with their own or modifies that one they have been known to just leave that switch dangling inside the door cavity causing random locks/unlocks. Simple to look for that one.

BrianW · 05-28-2019, 09:42 AM

Quote:

Originally Posted by 86Scotty

Have you pulled your rear right side door panel off? Another thing I've heard of is that on 2000 or so and newer vans the original door panel has a door lock switch in it and when SMB (or any converter) replaces with their own or modifies that one they have been known to just leave that switch dangling inside the door cavity causing random locks/unlocks. Simple to look for that one.

And older vans, too. My 98 SMB had the rear door power lock button hidden behind the SMB panel.

arctictraveller · 05-28-2019, 09:48 AM

Quote:

Originally Posted by JWA

AT what year is your van and does it have the Ford Remote Keyless Entry (RKE) option installed?

This time its a 2002, and yes it does have the RKE (I guess I called it a keyless entry module) Any idea how the lock circuit works? Are both sides of the solenoid hot and it actuates when one side is grounded? It's a little harder to understand when the factory wiring manual shows devices like the RKE as only an empty box with wires attached, what happens within that black box is not for us to understand I guess.

arctictraveller · 05-28-2019, 09:53 AM

Quote:

Originally Posted by 86Scotty

Have you pulled your rear right side door panel off?

Yes, and the switch is currently hanging by the wires, but was dry without anything touching it. I pulled it apart to clean the contacts, and while quite dirty, everything looked ok. Whats really odd here is the sudden onset of symptoms when I wasn't touching anything. The locks just suddenly went berserk, then just as suddenly, fixed themselves. (just like my 2001 did)

JWA · 05-29-2019, 06:21 AM

Quote:

Originally Posted by arctictraveller

This time its a 2002, and yes it does have the RKE (I guess I called it a keyless entry module) Any idea how the lock circuit works? Are both sides of the solenoid hot and it actuates when one side is grounded? It's a little harder to understand when the factory wiring manual shows devices like the RKE as only an empty box with wires attached, what happens within that black box is not for us to understand I guess.

Your symptoms of intermittent ghosting like this strongly suggests its electronic more than electrical. IOW not a simple chaffed wire or switch making poor contact.

the RKE box simply replicates the PDL functions as though one of the finger buttons has been actuated. I've seen a few YouTube videos where the braver souls have torn the RKE modules apart to replace one or more of the obviously failed surface-mounted electrical components, most often a capacitor.

And yes Ford doesn't readily release the schematics of their supposed propriatory devices like VSC servo's, the RKE modules--anything they can claim is available only from them and it'll cost what it costs. Of course such devices aren't produced after an unknown-to-me time frame once a model year is past so availability becomes a bigger issue.

Looking at the schematic you could wire around the PDL function of the RKE if it can't be repaired or a good replacement found. Naturally this all assumes it is the problem.

Nothing specific from me sorry to say but I hope this gives you ideas how to proceed.