Cadillac Tech Tips - How to fix it Discussion, How to Clean Window Switch Contacts 97 SLS in Item Specific Cadillac Discussion; OK, so the driver side window in my 97 SLS rolled down the other day, but wouldn't roll back up. ...
OK, so the driver side window in my 97 SLS rolled down the other day, but wouldn't roll back up. After getting two switches from the junk yard that didn't work 100% (one rolled the window up, but not down, the other had the opposite problem), I tried taking apart my original busted one to see if I could clean up the contacts/fix the problem myself. So the following is what I did to get the thing working again. I took some pics and will post them shortly when I can add arrows/descriptions to the pics so you know what you're looking at. Unfortunately, the pics didn't turn out that great, but they'll get you going.
So for starters, pop window switch panel out of the door. A flathead screwdriver is useful here and you may want to pop the door lock panel to give yourself a little more room. Next disconnect all the electrical connectors to free the part...use your flathead again as some of those stupid tabs are a pain to push in. Now take a jewelers flathead screwdriver and pry just the window switch part away from everything else. At this point I suggest working at a bench on a piece of paper as the parts are kinda small and can get lost.
So for starters take the window lock push button off by simply pulling on it. This may require some tough pulling or maybe pliers, but it will pull straight up and off. Next, you need to remove the tops of all the rocker switches. They are held in place by tabs on either side and you'll probably have to break one side to free them up. I suggest using your jewelers screwdriver and only prying on one side until they pop off. I did that and only broke one side of two of the rockers so everything snapped back together when I was done.
Now turn the switch module over and remove the white plastic bottom to expose the circuitry underneath. There are tabs on either side of this thing that catch on the gray plastic so I used two jewelers screwdrivers here (one on each side) to pry the gray plastic away on one side while I worked on the other side. Once you slide the white plastic part off over the exposed copper conductors, you should be able to see the circuitry
inside the switch. Next use your jewelers screwdriver to pry the gray housing away from the switch circuitry. BE CAREFUL NOT TO PULL ON THE TOP GREEN CIRCUIT BOARD WHERE THE WINDOW LOCK SWITCH IS BECAUSE ITS PRETTY FLIMSY. You can also push on the switches from the other side to get the circuitry out of the gray housing.
So at this point it might be a little more clear why your switch isn't working. My original and the switch from the junkyard both had black junk on several of the contacts that can't be good for electrical conductivity. To clean the contacts, you need to remove the clear plastic rockers by freeing them at their pivot points. When you do this, you'll see that below the rockers, there are two spring loaded plastic tabs that apply pressure to the copper conductors underneath them that alternately break one connection/make another connection depending on which way you rock the switch. When you have the rockers removed, the conductors will fall out if you turn the switch module upside down assuming they aren't covered with too much junk. Make sure you clean the contact point on the switch module as well as on the BOTTOM of the copper conductor piece that moves back and forth. I just scraped away all the black junk with my jewelers screwdriver.
So there are other things to check for at this point besides just the black crap. My original switch didn't work any more because one of the plastic pressure "tabs" had warn away and wasn't moving the copper conductor any more. To fix this I added a big drop of epoxy to the end of the pressure tab to make up for what had warn away.
The switch from the junkyard didn't work because the tabs that the rockers pivot on broke so the pressure tabs once again weren't applying any pressure to the copper conductors. To fix this I drilled a hole through the pivot point in the clear plastic piece and used a nail as the new fulcrum.
Another problem that I think I created was that I bent one of the copper conductors that move back and forth and it no longer hit the contact so you might have to slightly bend those to make sure they touch. An ohm meter is useful here to ensure things are making contact where they should be but not shorting to other stuff.
While you're in here you can replace the little 12V lamp that lights the switches if its burned out. Its in the middle of the circuitry between all four switches. Its covered by a little yellow rubber condom that you can remove and reuse if you want to maintain the same color/brightness of light. I smashed the existing burned out bulb and then soldered in a replacement that I got from the junkyard from the small lights that shine down on the switches on all the doors.
So to put everything back together, just snap it all in place and plug it in.
If you catch this post in the next week and don't want to do all this crap to get your windows working, you can bid on the switch I fixed on ebay.
OK, so I took some pics that didn't turn out that great and they are too big to load on the website anyway. I could compress them, but then they'd look even worse so I don't think its worth the effort. If you want to have a look at what I did, just send me a message with your e-mail and I can send them to you. However, if you've got some common sense, once you get into this little project, it should be pretty self-explanatory.
So for starters take the window lock push button off by simply pulling on it. This may require some tough pulling or maybe pliers, but it will pull straight up and off.
^This. It can take a lot more force than one might consider reasonable.
As soon as i got the switch assembly out and saw ALPS, i had an idea what i was dealing with, and was instantly transported back in time to my home audio (“stereo”) repair career (1980s-first half of 1990s). For those who don’t know, Japan-based ALPS has been and apparently still is one of the world’s primary purveyors of controls and switches for “consumer” electronics. Upon seeing the ALPS logo then coming here and finding the sage advice from digitalcaddie about pulling straight off, i went straight for my vintage electrical tape-covered soup spoons and symmetrically pried off the button.
Apparently ALPS/GM never meant for the rocker buttons to come off—even knowing what to expect and being careful, i still broke one side of one of mine, and nearly broke others (and my clever solder-a-wire-on fix failed, so nothing here about that). It’s exactly what one would think: under the silver decorative cover is a dark plastic inner square, which on each side has a small rectangular cut-out near the bottom edge, centered on the sides. These cutouts latch over small protrusions in the clear plastic inner rectangle which is part of the switch which moves the actual contacts. If one can get in and gently pry the outer rectangle sides away from the inner rectangle protrusions, the buttons should/would/could come right off. I found accessibility abysmal to impossible.
The “black junk” is the residue of arcing, and yes for sure it all needs to come out. I cleaned it with my favorite petroleum-based solvent, until all contact surfaces were clean and shiny. Note that the contacts are mildly asymmetrical (the end contact “feet” are different sizes), so be careful to note the orientation before removing them. (No, i have no idea why they’re asymmetrical.) After cleaning off the arcing carbon or whatever residue, i used my favorite pair of electrical contact cleaners (DeoxIT red then gold) to ensure minimal arcing and a longer life.
Unless you like doing things like repairing this sort of switch assembly over and over again, be sure to continuity check all possible switch combinations before reassembling! Another failure mode of these switches which hasn’t been discussed yet is loss of continuity of the copper straps/busbars at the swedge points. Why these connections are not more electrically secure is beyond me. I found one open and one marginal swedge and soldered across each one, instantly restoring continuity and fully repairing the switch. I didn’t solder across them all, but if the switch assembly acts up again due to any more of these failing, i will do them all. Because of this design issue, it is my belief that all of us will be better off fully repairing/improving the switch assembly we have vs. buying a new one… unless mechanical parts are broken and not readily repairable.
Due to the difficulty of getting the button caps on and off, i drove around for several weeks with the caps off, being very careful not to let anything fall into the switches. I pressed on the upper and lower edges of the clear plastic rectangles to operate the windows, and operated each one several times to ensure that they all worked. It’s now been about 2 months since the repair, the button caps are all back in place, and after (during the initial repair) un-jamming the mysteriously jammed driver’s window mechanism, all 4 windows work reliably for the first time in many years.