Recently developed a problem with the driver side door power lock that would not unlock with either the remote or the door switch. This also caused a problem with the dealer installed alarm which kept going off because the driver door would not unlock.

I am creating this post to share with others how I fixed it myself after some research and help from this forum...

1998 E150 high top full conversion van done by Kustom Creations who is now out of business.

Some troubleshooting advice:

At whatever door lock that is not working disconnect the connector on the power lock solenoid which should have 2 wires. Get a voltmeter and check each wire by connecting 1 voltmeter lead (red) to 1 wire and the other lead (black) to ground then move the switch on the door to lock or unlock and check that you are getting voltage. Check the other the same way. 1 wire will be for lock and the other will be for unlock. I had no voltage to unlock. This eliminated the switch. Also if the driver door switch is locking and unlocking all of the other doors this will tell you that the switch is good.

The next item to look for is the RKE (Remote Keyless Entry) module normally located behind the driver seat mounted on the sidewall. However this module is relocated because of the conversion.... My RKE was mounted in the same area but just lower because of the large window that was installed just behind the driver seat area. I removed the rear radio and there was an opening in the sidewall and the module was mounted there. My RKE module was made by TRW and has a removable cover which I opened. There is a circuit board inside and I checked and resoldered all of the legs that were for the connectors which some folks have posted that this fixed their problem but it did not fix mine... I kept looking at the board and found that 1 of the legs on a relay had become unsoldered. Very hard to see even with a 10X magnifying glass. The relays are the small square looking things on the board. I resoldered all of the legs on all of the relays and it fixed the problem. The door power lock now works and the alarm now works normally.

A new RKE from is over $200 and the remotes have to be programmed.

A lot of posts say its the door lock solenoid but check for voltage first and save money.

Also because of the alarm coming on I was unable to start the van. I finally found the valet switch. Mine is a small push switch located by the driver left footwell in the cutout for the parking brake release handle.

I hope this helps someone, it saved me lots of money...

 

Thanks for sharing your findings 007.

The biggest take away you offer is properly conducting a test of any failed device before simply replacing it. Yes most often it is the device itself however as you found it was another part in the control circuit or wiring.

We see far too often those who jump in feet first swapping out a part only to have the same failure, finally seeking another solution. Sadly I've stopped feeling any real remorse for them since there's more than enough info and those willing to help it doesn't make sense to go about repairing something so haphazardly.

BTW any RKE on Ford vans is a PITA---next new-to-me E250 I get will have that system eliminated long before the build out of the interior begins.