Door lock not working but 'trying to'

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rlyoung
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Door lock not working but 'trying to'

Post by rlyoung »

2001 Astro AWD LS
My passenger door is not locking or unlocking electrically, but is fine manually. The other doors work remotely as normal. I can feel a slight kick (it's trying to move) in the manual lock/unlock knob when I try to lock and unlock the door via the remote, so it seems like the actuator is getting 'some' voltage. My guess at this point is that the mechanism need lubrication? The ease with which I can move the manual lock knob up and down is the same as for the working drivers door. I haven't tested for proper/full voltage at the actuator since I haven't yet removed the door panel. Any advice appreciated.

Topic author
rlyoung
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Re: Door lock not working but 'trying to'

Post by rlyoung »

I just found this post referring to an internal fuse that might be bad. I've bypassed such a fuse in one of my window motors and put in an inline fuse. I'll add this to my diagnosis.

Weak power locks: viewtopic.php?f=62&t=9749&p=93944#p93944

Topic author
rlyoung
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Re: Door lock not working but 'trying to'

Post by rlyoung »

Update and a question.

I bench tested the actuator and it did pull the arm in and out, but not enough to lock/unlock the door. The internal fuse/resistor was maybe 3 ohms, so I left it. Later, just for fun I tested it again bypassing the resistor, and it was much stronger. It now operates the door, and no fuses blow. The action is so momentary I don't know that I need to replace the function of the resistor with an in-line fuse or resistor. I don't have kids that would lean on any switches. Should I put in a fuse, and what value? Or, say, a 1 ohm in-line resistor? I'm not sure exactly what I might need to protect, the circuit in general or the motor windings which now have no internal resistor which cut the amperage a bit.
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Re: Door lock not working but 'trying to'

Post by MountainManJoe »

The bimetallic strip protects the motor in case something gets jammed, switch shorts out etc. It's a tiny motor and not designed to run for very long without burning itself out. Fuses and resistors aren't suitable.

It's a 19 year old vehicle so your choices are slim. See if replacement parts exists. You can ask your local parts dealer or search online (rockauto.com is good). Junkyard parts won't last very long. Or just bypass it, accepting the possibility that the motor might burn out some day and you'll have manual locks. I think the motor is the weak point so at least you don't have to worry about frying your wiring.

Topic author
rlyoung
I am smitten with my van
Posts: 34
Joined: Wed May 18, 2016 9:01 am

Re: Door lock not working but 'trying to'

Post by rlyoung »

Thank you for responding. I measured the current draw this morning and it was 5.5 amps with the overload component bypassed, and to door is locking/unlocking fine. I think I'll live with this and see how it goes. The van is used maybe once a week just by me, so the lock doesn't get a lot of cycles.
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