Since a few days I have some issues with the tailgate of my 1979 Buick Estate Wagon. These are the 2 problems I have: #1: the glass will only go down, not up anymore #2: after using it as a tailgate once it now only wants to open as a tailgate, not as a door anymore. I bet the 2 issues are related. I don't have this car for that long yet, and the previous owner said it won't open as a tailgate. A few days ago I wanted to see what's up and see if I could fix it. At that point the rear window worked just fine and it also opened as a door. I used it like that for weeks. After lowering the glass and trying to open it as a tailgate it worked just fine. Before I knew it I had a tailgate. But after closing it up again I wanted to close the window, but it just didn't do anything. And I couldn't open it as a door anymore. It feels like I can't turn the outside doorhandel down as far as normal. And therefor the hinges won't unlock (at least not the lower right one, that's for sure). All together I've been staring at the inside of the tailgate for hours now. With a flashlight, poking around with a screw driver. Trying to make sense of the whole mechanism. It's not the window motor. The window motor get's power on the 'down' wire (white/tan) but not on the 'up' wire (blue). With an extra wire I switched it over at the connector so I could at least get the window back up (the car was stored outside at that time). So anyway, the window motor still works up and down. Can anyone tell me how the window switch works? When I turn the key (at the ouside door lock) to the left the mechanism inside pulls a part of the switch up, and window will go down. When I turn the key to the right nothing happends. It won't push that same part of the switch down, it just won't reach that far. I tried it with a scew driver, but there's still no current on the 'up' wire. But again, I'm not sure if the window switch is supposed to work that way. I get how it works for 'down', but not for 'up'. I'm glueless right now. I quess all 77-90 GM wagons have the same tailgates, so I hope someone can shed some light on this for me. I bet both issues are related. Sorry for the long read, tried to explain it as detailed as I can. If anyone has some scans of wiring diagrams for these vehicles, that would be great also. Or some scans out of a Fisher Body manual about the tailgate. Scans like that would be very handy (I have some GM and Fish Body manauls but from other years).
Most GM switches are very simple in principle. They are also bad to corrode and cause a short, or not work at all. If you pull the switch from the dash you should find that it comes apart very easily and the contacts cleaned with alcohol or starting fluid. That would be my first stop now that you know its getting power on the down side of the switch and not the up side. *sorry, i didnt see the part about the key switch*
if you are having the same trouble with the window at both the dash switch and the rear key switch, chances are it is not the switch. It sounds like something mechanical within the tailgate. 1st thing to do buy a service manual and a chassis manual, usually cheap on eBay (some even have downloads - I have not tried that)
I don't post a whole lot on here, but I got a little update on this. I didn't pay much attention to the tailgate the last couple of weeks. But it really started to bother me, so armed with a 1979 Buick Fisher Body Manual this time I went at it again. The problem is most likely in one of the build-in blockout functions. Probably the one that prevents the lower right lock to unlatch when you have the tailgate down (in case you would turn the outside handle, because this would result in a tailgate haning by only 1 hinge, and it will probably drop on the bumper). The whole problem started when I opened it as a tailgate that one time. The window switch is just fine. But since this blockout function is still active it prevents the window from going back up again. Even when I 'loop' the block-out' switch. Because the whole mechanism just won't turn enough (when I turn the key to the right) for this one rod to push a part of the window switch down (still won't reach that far). The door handle won't work, and I can't move the inside knob either. So it's probably this block-out thing. It just blocks the whole thing and won't let you use it as a door. Does anyone know how the lock works? Since it uses a 'lock actuator' and some wires are involved....Pretty much looking like this: http://oehq.com/Partpix/NUPjpg/DLAG001.jpg What does it do? Is the lock electronically controlled? Wires are going to a relay behind the right kickpanel. I probably need to find the solution somewhere in the right upper hinge (that's where the block-out functions are). But I'd love to know how this lock system works. Maybe I can somehow unlock it (as it seems to be locked).
Wixom is the MAN for this, and here's how he did it! http://www.stationwagonforums.com/forums/showthread.php?t=6408&page=6 You might want to read the whole thread, because its amazing work! http://www.stationwagonforums.com/forums/showthread.php?t=6408
uh...Norman, I don't think those links are really helping me :confused: I'm not going to make my wagon a 2-door wagon. I've seen those pics before, great stuff though! Awesome work!
David's is also a clamshell - your best bet is going to be joe_padavano he is an Oldsmobile guy but has a Caprice or something PM him
Thanks, I'll try and PM him. Mine is not a clamshell though. Just a 3-way tailgate like all the 77-90 boxy GM wagons have.
Have you tried bumping the bottom right of the tailgate to make sure the bottom right latch is tight? Most wagons have the block out features to block out the "other" feature when one is in use. So if your mechanism is being told that the tailgate is down, it wont allow the window to go up, and it wont allow the exterior handle to work. As youre trying things, a good spraying down with WD40 may free up something thats binding. its hard to see inside the doors, and its really tough when you dont have a reference model that works properly to look at so you can see what moves and what doesnt.
You just found the perfect argument for a second wagon! A Reference Model! "Look honey, these are rare, and I need another one in perfect condition to check with!"
Coming into this thread late, so I don't know if you've fixed the problem yet. The window motor wiring runs through a two wire connector that is routed to the key switch. The rubber weatherstrip at the base of the rear window is usually deteriorated, which allows water to get in and corrode this connector. This happens on my 84 Custom Cruiser (same wiring) about every six months. I have to take the inner panel off the tailgate and clean the connector terminals, then it works again. Note that it takes quite a bit more current to raise the window than to lower it, which is why it goes down but not up. The low current can flow through the dirty terminals, but the high current won't. As for the gate vs. door opening, this is almost certainly due to the latches not being closed all the way. The bushings in the LH lower hinge wear on these wagons, which requires you to slam the gate to get the latch closed. The latches are interlocked so that if it's open as a gate, you cannot open it as a door at the same time (and vice versa). It's possible that the interlock cables need to be adjusted, but my money is on the latch not being closed due to worn hinges and a sagging gate. Fortunately my 84 has the fiberglass tailgate, so the hinges are not worn, but my 86 Caprice has the metal gate and worn hinges.
