Dodge Caravan 2005 driver door lock

Wildie

All the door lock/unlock functions work except for the drivers door....
It will neither lock or unlock anything. The lock will work from the passenger side.
I removed the switch from the door and tested it with a VOM.
In the normal position the resistance was rather high, in the lock position its was lower and in the unlock it was lowest.
I measured the voltage coming from the body control module and it was 5 volts DC. This was open circuit voltage.
If anybody has any ideas about this problem, I would be most appreciative!

47_47

You should get a schematic of the circuit. Newer cars have a majority of the body electrical components routed through the BCM.
I'd pull the right switch and compare its resistances and voltages with the drivers switch. You could also check the wiring between the door and 'A' pillar and behind the left kick panel for nicks, water intrusion or corrosion.
After the visual, get a diagram, electrical parts are not returnable.
Possible causes
switch
wiring
terminal tightness
BCM

__________________
What we've got here is... failure to communicate. Some men you just can't reach. So you get what we had here last week, which is the way he wants it... well, he gets it.

Wildie

Thanks for your reply, 47_47.
I'm reluctant to remove the passenger side panel, as I had such a hard time removing the drivers side.
Of course I never noticed a screw down at the bottom, and ripped the panel off the screw.
And then the nylon mounting clips were a SOB.
To remove these, I damaged several of these.
I think that I do have continuity from the switch to the BCM as I can measure 5 volts DC on these leads.
The van has just run out of its extended warrantee, so I'm thinking that I should just trade it in, just in case its the BCM. (which I believe is really expensive)

sssalas

Check wiring, with door open cut the rubber insulation around all those wires that run from door in the door jam area, there might be a short to ground there. If wires are okay, I'd check or get a known good switch from the junk yard.

Wildie

I like your idea about getting a junk yard switch. I'll try that!
Thanks!

JVcar

Here's part of the wiring diagram that shows how a reference voltage is pulled to ground by a series of reisitors in the control switch when the it is operated. A scan tool is best to help diagnose the cause but is certainly much less expensive than replacing the vehicle! Call your service technician for a diagnosis; you can always reserve the option to repair yourself after the cause of failure is identified. Good luck...

Wildie

Thanks for your reply JV! I'm unsure what you mean by a scan tool? Is this the tool that 'reads' the car computer?

JVcar

Yes, that is correct. A scan tool communicates with the vehicle's computer controlled systems. Information is retrieved and displayed such as DTC's or diagnostic trouble codes, parameter values such as sensor input and output data. In your case, the body control module may display data and other information regarding the power door lock switch and may have a stored DTC fault code to aide in diagnosing. It basically lets the technician "see" what the computer sees and how it's controlling the outputs. In many cases, the output control can be operated through the scan tool. Hope this helps.

Wildie

Thanks for the explanation. I was aware that the 'puter' could be read, but was unaware that the BCM was linked also!
There is a BCM patch offered by Dodge corp. and I had this patch installed for $50. Unfortunately, it didn't resolve the problem completely.
When this all began, none of the electric locking worked. Including the locking of doors at 15 mph.
After the patch, everything was good, except for the drivers door lock function.
I've been considering trading up for some time, and rather than pay for a new BCM, I think that i will proceed with this!

Wildie

Problem is resolved! i bought a '09 Montana

47_47

Well, at least you didn't throw parts at it!

Good luck with your new ride.

__________________
What we've got here is... failure to communicate. Some men you just can't reach. So you get what we had here last week, which is the way he wants it... well, he gets it.

Wildie

Thank you! I was looking at new tires, the a/c was always leaking, a grinding noise was coming from some where up front, the BCM ($750) probably needed to be replaced.
I'm sleeping better, knowing that i have warranty for the next 3 years.