KauaiCorvette

I have removed the drivers side door panel on my 1979 to find out why the Power Door locks and the interior door pull **** for that door won't operate. Apart from being old and needing to be rebuilt, the problem seems to be that the door latch mechanism is too stiff to be operated. I can move the lever up and down and make it operate, but with much resistence. I would like to clean and lubricate the mechanism with lithium grease, but it is difficult to access through the small opening. My question is, must I remove the enitire lock system to clean and lubricate the door latch mechanism or should I simply apply the lithium grease through the opening to the mechanism and work it in the best I can. I hope to replace all of the components this spring, but I want the lock to operate in the meantime., otherwise I cannot really secure my car in the rare occassion of leaving it in a parking lot. Anyone with experience care to offer their advice? I am doing this work today only and must either fix it, or live with it for a while.

Eddie 70

Mine is a 70 but I think the lock mechanisms are much the same. I removed mine for almost the same reason. Mine lock mechanism was stiff and very hard to operate. I pulled my locks and cleaned them with brake cleaner and let them soak so that all of the old grease was removed. I then used white lithium grease to keep them lubed. That has been several summers ago, maybe 7 or 8 and they still work great.

KauaiCorvette

With the access openings being so difficult to work through on the 1979 model, I hope that I will not get it apart and not be able to reassemble the components through the openings. I am on my way to NAPA though and will buy brake cleaner as well as the lithium grease. Thank you for your reply. Any suggestions on the best way to remove the door latch mechanism on the 1979 so as to reassemble it without difficulty? Should I remove the actuator as well?

Eddie 70

Just be careful where the linkages go through the lock mechanism. Those little clips can be a pain to work around. The one piece of advice I would give is to be sure not to unscrew or adjust the linkages if you can help it. That would affect the operation on the mechanisms. You should be able to do it easy enough.

KauaiCorvette

Thank you Eddie. Unfortunetly, I have found another problem with the door lock. A short at the lock tumbler where the alarm wires connect. When the latch is operated manually, a tiny spark is visible there. At the same time, an electro mechanical click can be heard under the center console at the front of the auto shifter. An electrical switch with several wires connected to it on the drivers side of the console directly under the front of the shifter. I cannot identify this part. Maybe an auto neutral saftey switch? A better question is why is it effected by the short at the door lock? Any suggestions on how best to resolve this would be appreciated.

hunt4cleanair

Kauai

I had to restore/rebuild the power door locks on my 78 and ended up removing the door panel and the power window motor access door to really get at everything. The little hole will not allow you to get to all linkages that need cleaning. But you're right on with brake cleaner. That is what I used without having to remove the linkage. There is also a moisture barrier up by the door lock button that prohibits access from outside...this was first installed in 77 so your 79 has it as well.

I also learned that my actuators were shot. The plastic boot had disintegrated and the plungers would not "pop" when switch power was applied. I also found a short in one of the switches due to frayed wires with only one strand holding it together. So, you see once you get in there on a thirty-year old car, you may find many ills that need correcting.

Here's an article that was published in the now defunct Corvette Enthusiast that may help describe how best to proceed. Feel free to call or write with questions

Power Doorl Lock Repair

Eddie 70

I am guessing here since it has been a long time since I had my 79, but, mine had a factory alarm system installed in it. The way to arm the alarm was to manually lock the drivers side door with the key. The spark you are seeing is you making up the contacts for the alarm system. IF I remember correctly the alarm relay is mounted under the console. I think you are just arming your alarm system when you lock the door and you are hearing the relay pick up. You might try rolling down the drivers side window, locking the drivers side door, and then take out the t-top and see if that sets the alarm off. I think the t-tops, the doors and the hood are all switched to make the alarm do its thing. It has been since 98 when I had my 79 so I am going on memory here. Someone check me on this.

81pilot

I used Penetrol 90 on mine. Niether side would work, I just soaked it and let it sit and then did it again and again, it all works great now and has for over a year. The penetrol foams and finds its way into the crevices, and leaves teflon behind. If you are set on lithium grease, AMSOIL makes a spray red lithium product that will get in there too. Regular grease on an old part without a lot of cleaning first will make it worse.

Paul L

Be careful. Sometimes brake cleaner and paint do not mix well.

KauaiCorvette

Thank you all for your help. I completed the repair to the left door and then went into the right door for good measure. The Brake Cleaner worked well as did the lithium grease, although I did use the spray lithium grease as it was all the auto parts store had. Once it was all put back together it snaps open and closed just right. The sound of the alarm system click is still a bother, but I found that I will need to replace both lock cylinders anyway, so when I R&R them, I will take a look at those wires and connections for a short. I need to replace them both because the cams at the end are worn out and no longer turn the lever. They must have gotten stripped from trying to force open the sticking latch's. Again, thank you for your replies. Merry Christmas and a Happy New Year!