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rpmdiag, Tech and Instructor
Category: Pontiac
Satisfied Customers: 7060
Experience:  Since 1975
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2002 Grand Prix drivers front door won't lock with the

Customer Question

2002 Grand Prix drivers front door won't lock with the switch. All other doors work from driver's front door for lock and unlock.
Submitted: 11 months ago.
Category: Pontiac
Expert:  rpmdiag replied 11 months ago.

Hi, I’m Ron and I can help you.
I have been in this business since 1975 and also teach automotive repair. I am confident
we can resolve your problem together. Please understand that I don't know your skill
level. I can't see, smell, hear, or touch the vehicle either, so it may take a few replies to
get to satisfactory results. Please be patient!
I also try to give all of the information you may need, expecting a “positive rating” in
return. I will also continue assisting you after you have rated me, if necessary. If there
is any reason I cannot get a positive rating, please let me know why “in advance”, so I
can go another direction for you. I am sorry you’re having this problem; I’ll help you
through it.

This sounds like a bad switch or a wiring problem then.

Thanks, Ron

Customer: replied 11 months ago.
The switch works fine to lock and unlock all other doors from the drivers front door. It will unlock the drivers front door. it just doesn't lock it.
Customer: replied 11 months ago.
Ron, are you there?
Expert:  rpmdiag replied 11 months ago.

I'm here, please be patient. Then a switch contact or a bad ground is causing this.

Thanks again, and please don't forget to rate me in case you need me again later on.


Customer: replied 11 months ago.
I am sure that the switch is good because all of the other door locks will lock from this switch. If all of the other locks work from this switch then the ground is good. Can you send me a schematic of the door locks for my car?
Expert:  rpmdiag replied 11 months ago.

Separate grounds for each door, AT the doors. My database is down right now. Most of the time, it's in the wiring loom right at that door from opening and closing it all the time.

Thanks again

Customer: replied 11 months ago.
Can you tell me what color wire to check?
Expert:  rpmdiag replied 11 months ago.

Grounds are black.

Customer: replied 11 months ago.
What is the color for the lock circuit at the drivers door?
Expert:  rpmdiag replied 11 months ago.

my data base is down right now so I don't have that info. The best this for you to do now then is voltage drop tests. It works great for any wire, even grounds.

Thanks, Ron

Customer: replied 11 months ago.
ok. I'll check this out and get back to you in a bit. I have a hard time believing it is a ground if it locks and unlocks all other doors from this switch.
Expert:  rpmdiag replied 11 months ago.

Well it's broke, it needs power and ground to work. Which one is missing? You said the switches are good.