Hi; I just bought an '89 Suburban and am trying to get it on the road. It
has a tailgate, and the window doesn't operate properly. I found some
mechanical problems: the tracks are a little ratty (I'll replace them),
and the nylon wheels that run in the tracks are worn out (can they be
replaced without replacing the whole assembly?). The window goes down with
ease; I plugged in the power and put it down and it's still down! It
wont't go up; doesn't even try. I assume the switch is supposed to just
reverse polarity and the motor is supposed to run forwards or backwards. I
tested the voltage at the plug which attaches to the motor; I get +5.8
volts when I put the switch in the down position; -0.38 volts in the up
position; I was expecting -13V and +13V. I see a little switch at the
right latch assembly; looks like something to do with not allowing one to
operate the window with the gate open (or maybe not open the gate with the
window closed???) In the morning, I'll disconnect the switch at the latch,
and jump past it; then, next step, check the dash switch. Also, the keyed
exterior switch is seized (maybe that's the problem??). Any suggestions?
Thanks. Keith.

"stude-ious" <keith.barrett2 (AT) nospam (DOT) sympatico.ca> wrote

Bingo. When the interlock switch goes bad it goes down but not up. You can
replace the switch easily for less then $12 or you can just jump past it but
you must make sure the tail gate is fully closed each time you put up the
window. If the window is ever close when the tailgate isn't completely
close the window can shatter.

good luck,
mark

Hi Mark; Yup, that fixed the motor problem; thanks. I just cut the wire and
connected it back together, by-passing the switch. Changing the switch is
now way down on the priority list (hope I get to it before I shatter the
window!). Now, those little nylon wheels that run in the track need to be
replaced. I hope someone has new ones....I'll check with GM on monday.
Sure hope I don't have to get the whole assembly!
Keith.

"stude-ious" <keith.barrett2 (AT) nospam (DOT) sympatico.ca> wrote

I am not sure about the wheels but GM still carries all the parts for these
trucks. A few years ago I completely rebuilt the tailgate (new slides,
motor ect) and they had everything. You should get a catalog from LMC they
have almost everything for the truck except a new frame and sub-body...
Make sure you keep and eye on the rear wheel wells they rust extremely fast
and are hard to fix. As a side note if you have a 91 like mine you have to
tell the autoparts guy that it is a 90 or you will get parts from the new
body style suburban. good luck

http://www.lmctruck.com/scripts/mgrqispi.dll?APPNAME=WebLmc&PRGNAME=CatalogRequest &ARGUMENTS=-ATK,-ACSB

mark