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I am new to the forum and of course this is my first post.
I'm buying my first Corvette, it's a 1999 C5.
The thing is flawless but according to the owner it has only one problem, the driver (or passenger I can't remember what he said) power door lock doesn't work.
I worked as an apprentice at a few local auto shops my 4 years in high school, and another 4 years at another shop when I was in college. However I'm not sure what this could be. Partly as I'm not familiar with Corvettes (yet!)
Does anyone know how/why a power door lock would fail? Is there a motor/module I'd need to replace? Is this common on C5's? Could it be something as simple as a fuse?
Basically the most I know is that the door panel is gonna come off as soon as I pick it up and drive it home. However I don't know what to look for in terms of rectifying the door lock issue so I can have it operable.
I apologize if this is a "dumb" question or if it's been talked about in other threads. Lol I've had my fair share of bashings on Rennlist for my Porsche and 6speedonline for my Marauder.
I would really appreciate any and all advice and help anyone can offer.
You will need to know which door lock doesn't work. If it is the passenger door lock, does it work from the switch on the passenger door? Does it work from the switch on the drivers door??
Most likely culprit is the door control module. But it could be the lock motor. Need to answer the above questions before a lot more help can be offered.
Here is a link that will get you some more info about the DCM.
You can jumper 12 volts to the motor and see if it works. The door module just reverses polarity to lock and unlock. Door panel removal info is below. If the motor is good then you can jumper (just jumper wire, no voltage applied) the door switch connector to see if it is that or the relay. If you need the info on the switch to do that let me know.
In that picture 8VETTE7 posed from that Thread the lock relay is the one on the bottom. The unlock is in the middle. The top relay is for the heated mirror. The larger one on the right is for the windows.
Relays are dirt cheap. If you are OK with soldering you can fix it yourself or get a friend to do it. Relays are the same for both doors. Removal takes patience but replacement is easy. Just be cautious to not get solder on adjacent traces on the board.
You can jumper 12 volts to the motor and see if it works. The door module just reverses polarity to lock and unlock. Door panel removal info is below. If the motor is good then you can jumper (just jumper wire, no voltage applied) the door switch connector to see if it is that or the relay. If you need the info on the switch to do that let me know.
In that picture 8VETTE7 posed from that Thread the lock relay is the one on the bottom. The unlock is in the middle. The top relay is for the heated mirror. The larger one on the right is for the windows.
Relays are dirt cheap. If you are OK with soldering you can fix it yourself or get a friend to do it. Relays are the same for both doors. Removal takes patience but replacement is easy. Just be cautious to not get solder on adjacent traces on the board.
I think that Thread has the P/N and source for relays. If not let me know.
Let us know if you have any questions or need any more info. Please update and let us know when it is fixed so others can learn from your issue.
Mr. Sam
Thanks for the reply.
I just picked up the car today.
A few funky things I noticed were:
Passenger side door handle won't work when you try to unlock it from inside.
Key fobs (both) won't work. I don't know if its just the battery, but when you tap the fob you hear a slight noise as though something is loose in it. I opened it up and nothing was visibly wrong. So I locked the door manually (passenger door did not lock).
Power driver seat gave a slight hesitation moving forward, but after a few extra taps it went ahead (maybe lube the tracks?)
Lastly, driver's window isn't firm/gives slight rattle when you open/close the door. I'm used to pushing it shut maybe 50% of the time because I do that on my 911 so I immediately noticed.
No, does not sound like very serious stuff to fix unless you are saying there is no way to open the right door. Of course there is a way around everything.
You first need to remove the passenger side door panel and let's why you can't manually lock the door first.
Try a new battery in one of the FOBs and see what happens.
You probably need to lube the rails. I have info on that when you are ready. Otherwise in the interim it will move easier if you are not sitting in it.
You can look at the window issue when the panel is off. Even the regulators are inexpensive.
No, does not sound like very serious stuff to fix unless you are saying there is no way to open the right door. Of course there is a way around everything.
You first need to remove the passenger side door panel and let's why you can't manually lock the door first.
Try a new battery in one of the FOBs and see what happens.
You probably need to lube the rails. I have info on that when you are ready. Otherwise in the interim it will move easier if you are not sitting in it.
You can look at the window issue when the panel is off. Even the regulators are inexpensive.
Mr. Sam
Thank you so much for your help thus far.
I realized that when I press the lock button on the door, it makes a sound but nothing happens. Also, the climate control buttons do not eliminate when the headlights are on.
Is this something uncommon on these cars? It's nothing new to me but on my Porsche's it's usually just a fuse.
Sam... some say illuminate, some say eliminate... depends on where ur from. Kinda like prostrate or prostate...
Damn autocorrect!!
Sorry about that. Update:
Took it to the stealership to get the keys reprogrammed, key fob now works.
Doors do not lock or unlock. When you press the button inside, nothing happens but you hear a noise as though it's trying to lock. No idea what is going on there. Whether it's relays or fuses I have no clue.
As far as the climate control panel goes, but at night time or when it's dark outside the buttons do not illuminate when the headlights are on.
Possible fuse problem? Or is is it possibly an internal actuator/relay issue?
Mind blowing. My 911 had similar problems with the climate control but it turned out to just be a blown fuse
You need to go into the door to look at what is or is not happening and we can go from there.
On the HVAC there is power to the lights controlled by the BCM. I will have to look into that but not at home. Worked with a guy just a few days ago with the same basic issue. I said how to get the lights without the BCM. I figured it was bad from his diagnostics. He did what I recommended and he has lights.
Will find that Thread and post later. Not saying your BCM is bad as there are other things to look at to see if it is the actual dash unit or wiring.
You need to go into the door to look at what is or is not happening and we can go from there.
On the HVAC there is power to the lights controlled by the BCM. I will have to look into that but not at home. Worked with a guy just a few days ago with the same basic issue. I said how to get the lights without the BCM. I figured it was bad from his diagnostics. He did what I recommended and he has lights.
Will find that Thread and post later. Not saying your BCM is bad as there are other things to look at to see if it is the actual dash unit or wiring.
Mr. Sam
Thanks for noting about the HVAC lights. Please share what you have whenever you get a chance to. I'm not quite sure what a BCM is.
Could also be the unit itself?
In any event, I tried fiddling with the wiring underneath the accordion tube between the door and the car opening. Will be taking off the door panel tonight/tomorrow. Hoping this all gets sorted out.
The BCM is the Body Control Module and it does a bazillion number of things and is in the passenger foot well. It does things for the car similar to what the PCM, Power Train Control Module, does for the engine.
The BCM is the Body Control Module and it does a bazillion number of things and is in the passenger foot well. It does things for the car similar to what the PCM, Power Train Control Module, does for the engine.
Mr. Sam
Very interesting, thanks for that.
I located the BCM and fuse box under the passenger side footwell. I am going to swap out the 2 HVAC fuses (both 10 amp) and right/left door power fuses (25 amp) to see if they may be the culprits.
As per the thread attached thread, I can't tell where that plug is and what exactly I am looking for.
That plug is at the back of the dash unit. Let's fix the door and then we can work on the lights.
Thanks. This is where I've gotten so far. Replaced fuses for HVAC (no beans) replaced fuses 31-32 (I think) for the left door controls, no beans.
Now I took the door off, made sure the connectors were good, hit them with electrical contact cleaner, and still nothing. Had to reprogram my key after too.
This is what I'm looking at. Please let me know your thoughts, thanks.
Thanks. This is where I've gotten so far. Replaced fuses for HVAC (no beans) replaced fuses 31-32 (I think) for the left door controls, no beans.
Now I took the door off, made sure the connectors were good, hit them with electrical contact cleaner, and still nothing. Had to reprogram my key after too.
This is what I'm looking at. Please let me know your thoughts, thanks.
Behind the rubber
You hear a clicking noise from the DCM but zero effect on the door lock
Passenger power door lock
some say illuminate, some say eliminate... depends on where ur from. Kinda like prostrate or prostate...
