Thanks for the information on this forum.
It helped me get my door lock fixed on my wife's Honda Odyssey.
The lock on the door slowly got "lazier" over time. If I locked and unlocked repeatedly, the lock would have less and less actuation.
When I disassembled the door lock, and took out the motor, I drove the motor with a bench/test power supply and the motor would spin, but slow down over the next 5-10 seconds until it would not turn.
Since it was broken, I thought I'd determine "
root cause". I pulled the motor apart to look inside.
It looks like the ~10mm x 8mm plate that conducts electricity through to the contacts of the commutator increases in resistance with prolonged use and prevents the windings from burning out. I think that's why the motor ran slower and slower from start to about 10-15 seconds.
But the most interesting thing I found was the root cause. The plastic cap was full of black greasy. it was probably a combination of grease and worn particles. I cleaned everything out with a low viscosity spray, but it still didn't work very well. My guess was that the motor was drawing too much current probably due to the windings being shorted. However the bench supply said otherwise. It didn't read like the motor was shorted. I've seen where debris with grease can cause a low-resistance bridge and it turned out that was true. The crud that was stuck between the commutators was conducting electricity so less current was going through the coils. I used a pin to clean out the crevice between the two commutators and voila, the motor worked 20x better. I then reassembled everything the now the door lock is working. Total cost $0. Total time 3 hours.
These motors are only $6 on ebay so it's probably easiest to just order one before starting the job, but I didn't do that ahead of time and didn't want to wait for one to be shipped to me.
CLEAN THE GAP BETWEEN THE COMMUTATORS WITH A PIN. THAT FIXED IT FOR ME!
If they are any problem w/ me jumping in on this as well as sharing the info w/ my side of the forum?
