S/V/C 70 Door Lock Latch Repair...

[rspi]

POWER DOOR LOCKS NOT WORKING PROPERLY:
As the signature shows, we have a '98 S70. The power door latches stopped working properly. They would lock in the auto/switched/remote mode, but would no longer unlock. So, turn the key twice to unlock, only one of two of them unlocked, had to reach to the door to unlock them manually. Pain in the butt, expecially the rear doors since the latches are so far away.

THE PROBLEM:
The issue is that the latch power motors has a temperature protection chip in them. If you cycle them lock/unlock to many times in a short time, it will heat up and stop the motor from operating, to protect the motor. Over time, this chip wears out and stops current from flowing properly inside the motor. For some reason, which I feel is good, it will allow the motor to lock the door. However, it will not give enough power to unlock the door. Maybe over time it will also stop it from locking as well, however, for now it will still lock the latch.

SOLUTION:
There are a couple of options:
1. Purchase a new latch from the stealer. Our local place charges $175+ tax for a new latch assembly.
2. Purchase a used latch on-line. EBay has them ranging from $40 to $140. Mind you, these latches can last 30 days or a couple of years depending on the wear.
3. Source them from a junk yard which can already be bad since you can't test them on the car. I went through several of them before I finally gave up and learned how to repair the motor.
4. Repair the motor inside the latch. This is takes a little time, some skill, and a little supply material. You remove the latch, open the latch assembly, remove the motor, open the motor, remove the switch, install a solid electrical part to carry the current inside the motor, put the motor back together, install the motor, close and seal the latch, then install the latch back in the door. The only issue I believe exist with this method is that the motor no longer has the thermo protection. Run it 20 times and it may burn out the motor.

OPTION:
I am considering offering a service where I can rebuild these latches and have an exchange service where people can purchase or exchange them with me. Do you guys think this would be a worth while service? I do realize that you can't just ship one and wait for it to be repaired and shipped back, you won't be able to lock the car. So, I'll likely have to have a supply and allow people to order the latches, then credit back the core. I'd also be willing to offer some kind of warranty on them.

[Matty Moo]

The one problem your going to run into is the broken plastic/latch part on the unit.

[rspi]

The part that hooks to the button?

[m96ag]

I believe he means the part the activates the internal microswitch for the interior lights, etc.