I need a little information

I have a 91 940 turbo and the windows will not roll down.

I have checked the fuse so I know its not that.

really have NO idea what would cause all 4 windows to have no power at the same time other than a fuse.

Any help is appreciated

Thanks

 

Is it happening at main switch only or all the window switches?

 

Most likely a bad main switch pack...you tested the fuse correctly with a test light? Also, could be severed wires in rare cases...I would test for power at the switch first...if no power you either have a bad fuse or cut/disconnected wires...if power bad switch pack.

 

The windows don't work at the main or on any of the doors....

Yes I tested the fuse with a test light and even tried several new fuses just to be sure.

 

Power Window Switches
Overall Diagnostic Tips. [Dave Stevens] General tips on the power window system:

All window motors are connected directly to one side of their respective window switches and nowhere else. Only two wires are used for each motor with reversed polarity (either +/- or -/+) being supplied depending on whether the window is to go up or down.
All door switches receive their primary power (locally switchable) from fuse 8 which is in turn powered by a relay when the ignition is on (KPII). If any window works properly then fuse 8 and the relay are okay.
All door switches (except the RF passenger door) get their primary power from the driver door switch pod. The rear door switches get their primary power through the rear window lockout switch in the driver door switch pod. If any window works from the driver door switch pod then power is getting to the switch pod and almost certainly to all pod switches. The RF passenger door is the exception -it gets its primary power directly from fuse 8. That's why the RF passenger door can sometimes be operated locally but not remotely from the driver door. The reason for this is that it's simply a shorter wiring run from the fuse directly to the RF passenger door. The rear doors are powered from the driver door because of the rear window lockout feature.
o Secondary (remote) power is provided on a separate pair of wires going from the remote switches at the driver door to the respective door switch and through it to the window motor. As mentioned, the way the remote switch is depressed determines the polarity on this pair of wires making the window go either up or down.
It's rather an elegant design, especially as all the switches are basically the same, and I'm sure the first person to come up with it was grinning from ear to ear when they walked into the head engineers office.

If the driver door window switch pod will operate any window then power can get to all pod switches, but won't get through any faulty switches. If no driver pod switch works (and the rear lockout switch is closed) and the RF passenger door window switch works (meaning fuse 8 and the relay are okay) then you need to fault trace for the 12 volt supply to the driver door switch pod on the yellow-red wire coming from fuse 8 (a broken wire at the hinge area being the primary suspect).

Assuming the driver door pod has power but the window still does not operate, the problem would be getting secondary (remote) power through the appropriate remote switch over to and through the passenger door switch. At the switch pod, if you can test the window switch and make it work, then that switch is almost certainly okay. The problem would then be in the circuit (two wires) from the remote switch over to the passenger door switch or in the passenger door switch itself.

If neither switch controls the window, it's probably best to start fault tracing at the passenger door switch. Pull the connector off the switch. Connect the -ve lead of your DVM to a known good chassis ground point. You should (and in your case will) see 12 volts on the yellow-red wire in the open connector (pin 4) with the ignition switch on (KPII). Connect the +ve lead to the red wire in the open connector (pin 5). At the driver door pod, depress the RF switch for either up or down (I can't tell from the diagram). In one of those two positions you should see 12 volts on the meter -if not then you have a break in the red wire circuit back to the driver door pod switch. Repeat the test with the +ve lead on the blue wire in the open connector (pin 3) -if you don't see 12 volts in the opposite position then the problem is in the blue wire circuit back to the driver door pod switch. If both tests can see 12 volts on the red and blue wires (in opposite positions) then the wiring is okay and the problem lies in the passenger door window switch itself -try exchanging it with another single door switch.

For circuit tracing, one side of the driver door pod RF switch starts out as a grey-red wire going to one of the large connector blocks at the left A-pillar, then over to a connector block at the right A-pillar then becoming the red wire that goes to the RF passenger door switch. The other side of the driver door RF remote switch is a blue wire and stays blue through the same connector blocks to the passenger door switch.

Using a sharp pin to probe through the wire insulation you should be able to isolate a break, most typically at the driver door hinge area.

If you want to start moving switches around for testing, one thing to know is that not all window switches are created equal. You can obviously tell by part number. You can also tell if they're functionally the same by testing for an internal jumper between pins 3 and 5. Note that 940's have an illumination lamp in the two forward switches at the driver door, but are functionally the same as non-illuminated switches. The four switches in the driver door pod are all the same and will (normally) have pins 3 and 5 internally jumpered. The single switches in all the other doors are the same and never have the internal jumper.
Non-jumpered switches can be used at the driver door if the jumpering is done externally between pins 3 and 5 on the connector. That's something worth knowing as used driver door switch pods are typically sold as a unit and they're not cheap. Also note, you cannot modify an internally jumpered switch to function like a non-jumpered switch.
Switches Don't Operate the Windows. Preventive Maintenance Tip [Steve Ringlee] The window switches ALWAYS fail at the worst possible time when it is freezing cold or pouring rain. Keep a used, spare but working switch in the car so, if need be, you can quickly pry up the switch carrier, disconnect the failed switch and connect the correct harness connector temporarily to the new switch, and raise the window. You can repair the assembly when you get home.
Removing the Switches.
740/940: Behind the switch cluster in the recessed area where the inner door lever lives there is as plastic screw. Turn it and pop it out. Now gently pull up that whole plastic trim piece in which the cluster rests. The switch block will come up and out of its mount point by gently prying up on the edge of the plate that the switches are mounted to. You may need to push at the carpeted trim that is behind the cluster to remove the plate. The switches snap into this plate from the underside. Gently push them out from the top or pull them out from the bottom. Disconnect wires and attatch to the new switch. Tips: be careful in removing the connectors and switches from the plastic carriers. It's best to first remove the red switch connector carrier assembly as a unit (two red tab locks on the ends and two in the middle, using a jewelers screwdriver to unlock the tabs), then remove the electrical connectors from the carrier. Then remove the switches from the top plate by carefully unlocking the tabs holding them in place and push toward the bottom of the carrier. [Tip] The black locking tabs in the plastic switch carrier are very fragile; bending these back to remove the switch often causes them to fracture. If you are not planning to repair the switch, use an X-Acto knife to slice the white nylon locking tab on the switch body and remove the switch without having to bend the carrier tab back. Pop the new switch in from the bottom of the carrier and you are all set.
960/90: [John Sedlak] Be patient with small plastic parts. Remove the small cover near the door handle; be careful as it is likely to break ($6.00 at dealer). It is held in place by a black adhesive tar. Next remove the two 25mm torx screws and gently pry up the assembly. The switch pod and tray are held in place by a plastic retainer. You can wiggle the switch pod free of the retainer and away from the door. The window and mirror wiring and clips are color coded. Take out the bad switch and replace with new. Sometimes these or the whole assembly ($30) can be found on Ebay. The small cover will stay in place without adhesive if the small tab on top is intact; if not you can use a hot glue gun to adhere different plastic pieces as substitutes.

Switch Repair.
Repair. You can take apart the individual window switches and clean them out. The switch pivot has a bit of oil or grease on it and some of it gets on the ball bearing contacts, causing dirt to get stuck and faulty contact points. The same may be true with your child safety locks for the rear windows. It worked for mine, but I think I need to clean the switch once more as it only operates correctly 80-90% of the time going down, and all the time going up. I was even thinking of replacing the switch itself if that didn't work. No experience on the power relays, though. [More] These are fun to fix. Pop the switch out (see below: I usually wind up doing them all as long as I'm there) and pry the side off the little nipples so the cover comes off each switch. Be careful since there is a spring in the rocker, you don't want to lose it. Take out the little metal "lever" and use some very fine sandpaper to neaten up the contacts on the lever and the contact points inside the switch. [Tip from John Yuristy] . I wouldn`t use sandpaper or steel wool on contacts, some are just plated and you will remove the good stuff. [Jeff Pierce] I tinned them with solder for a better contact surface.