hi, i have a 94 940T that I've been getting online (you may recall the thread pre-COVID regarding a $200 940T in my neighborhood...) and have encountered a few problems that I'd appreciate any help/tips on....

- the sunroof will retract fully and close 95%, but the sunroof gets stuck on the black plastic windshield at the front of the window; then the sun roof stops moving. It appears that the black windshield is supposed to fold down as the window moves over it, and I tried cleaning/lubing the springs but without any success.

- the power windows in the back seats don't retract fully, regardless of using the front driver or rear seat switches. I cleaned one switch in the rear but it didn't make any difference. both rear doors 'bulge' as the window reaches its max depth, suggesting to me some sort of interference in the door. any tips of taking the door apart to check this out?

- the front driver seat will not move forward nor backward, but I can adjust its angle and height. it has the electronic controls. I suspect there's, again, some block on the track and that it's not a motor fault. YET, the passenger side seat is stuck on its mechanical track. I am more looking for advice on the driver side here since I doubt it's a motor fault; the passenger side I just need to take out and examine.

- the blower motor for the climate control system will audibly operate but no air moves out of the vents. I currently do not have an AC belt installed, but I don't think that matters. No air moves regardless of what vents I select or what power I choose for the blower.

- I don't have a horn?? are the horns for 940s supposed to be mounted in front of the intercooler/radiator (like on a 240)? if so I just don't have one. but the fuse for it is good and yet no horn sounds when I press the button.

any advice and tips for these problems is much appreciated! thanks yall.

 

1 You have to bend the center section of flip up wind deflector so it moves down enough to allow the sunroof to pass. (unless the parts on the sunroof that push down are missing) If it has slipped on the sunroof gear you may have to realign the motor.

2 Are you sure they are not only meant to retract 3/4 - does the cutout for the rear wheel arch in the door prevent the window from going down all the way?

3 The switches go bad, get a poor connection inside, sometimes flicking the switch many, many, many times will get a better connection and make it work - sometimes. Never have seen a bad motor, cables yes, motors - no. You can move the seat using the Pre obd Volvo scan tool - the one that no-one has anymore. (i've got one!)

4 That system relies on vacuum to open the vents - a vacuum switch is attached to the vent direction control - on the right side center section of the firewall is where the vacuum attaches - perhaps there is a broken or damaged vacuum line under the hood or pinched under the dash.

5 Horns are mounted on one side under the front of the car - switches in the steering wheel go bad, pry one out out the steering wheel and ground the black wire to something - that should sound the horn.

 

1. To fix that I put two sockets at the edge of the wind deflector to keep the ends from bending and push down in the middle--that usually fixes it, it doesn't take much.
2. What you describe for the driver seat is most likely cables problem, may be that motor. Have to take the seat out and check the tracks also. Same for the pass. seat. Volvo seats are prone to sticking especially after years of being in the same position.
3. The windows only go down about 3/4 of the way, no more.
4. Or go under the left front of the car, verify horns are present and test them, apply + -, see if they make noise.

 

1. totally agree with Lev
2. the bolts holding the window guides or motor might be loose causing the door card to bulge. Remove the red safety lens first by pulling it straight out of the door. Lie down under the door and pluck the three white keepers from the bottom of the door. Carefully slide the speaker grille forward (they break easily). Remove the screw in the door pull, remove the door lock pull. You should be able to lift the door card off the door and remove the wiring. Now you can access the window tracks and motor.
3. agree with cable analysis, I have read about a cable fix for the fore/aft motor but I have long since forgotten where. That is your problem, it pulls away from the drive track (not the motor)
4. agree with vacuum analysis, I would first examine the black and white check valve on the firewall, slightly off center on the intake manifold side of the engine.
5. the horn buttons are difficult to safely remove (I actually pulled the airbag to check mine). Turns out the connectors at the horns (looked ok, tested ok) but were badly corroded. I replaced the horns with FIAMM horns but needed relays to power them.

 

3. On second thought, a cable problem would cause an uneven left-right movement, unless both cables are bad, and then you'd hear the whirl of the motor, no movement at all would be the motor--

 

IIRC, the issue with the seat motor cables is that one side is driven direct by the motor, but the other side is driven by a cable in a sheaf. from the most common failure mode, the fix is to trim a little off the end of the cable where it goes onto the motor.

 

thanks for the thoughts guys. I put WD40 on the passenger seat rails and they're fine, and after toggling, the driver seat is also mostly working too.

i have one question unrelated to the OP: i don't have a boost gauge installed yet, but what should I be getting out of the hole under normal acceleration on the dash gauge? if I mash the pedal I get the needle to about 1:30 if the black/white split is noon. I think I have a boost leak, but I replaced the hosing from the compressor nipple to the T under the intake manifold, and between the waste gate actuator and the the compressor housing. I read there's a nut on the wastegate arm that, if incorrectly adjusted, can result in an ajar wastegate. i need to look into that.

 

i think I used to see max boost on my 740 T in 3rd gear, climbing a long steep grade, wide open throttle at upper middle RPMs, and it might go as high as 2 oclock on the gauge.

re: WD40, that might have loosened it up, but its alousy lubricant, its mostly kerosene with a bit of very light oil. I'd wipe it up as much as possible, and grease the seat rails with white lithium grease for longevity.

 

thanks pierce. I read elsewhere that, absent a gauge, it's basically anyone's guess what the turbo is putting out in terms of boost. it appears that the 940 doesn't rocket out of the hole or anything but on the highway, man it'll pull 55 to 75 in a few seconds!

and thanks for the heads up on the WD40. I'll put some grease on them. i presume white lithium is also good for lubing hinges and locks?

 

key locks, I would use liquid graphite, like the Lock-Ease sold at most any hardware store in a little blue squeeze bottle. white graphite is good for door hinges, hood hinges, etc, it comes as a foaming aerosol, spray on, work the hinge a few times, wipe off the excess.

 

As noted earlier, my needle also swipes to about 2 o'clock under hard acceleration. My engine and transmission are still original, and my 0-60 time is still about 10 seconds, no burnout. Like yours, the rolling acceleration is very good too, shifting a little north of 5000 rpm WOT, smooth as butter. LOVE THAT CAR

 

i love my 940T too. wow, sun roof and all - it's great. the only thing I'm a little caught on still is the out-of-the-hole acceleration. it'll fall flat on it's face unless I give it pretty decent throttle. not sure if that's normal or not. but like I said, once it's in 2nd gear or so, it'll be more responsive.

 

hard launches in 1st gear eat up your drive train anyways.

 

well I installed a boost gauge and my suspicions were right, I'm only getting about 4lbs of boost under full throttle. however, removing the hose from the wastegate actuator results in overboosting to 15lbs +. so my suspicion was the wastegate actuator being incorrectly adjusted and the flapper being ajar in the turbine housing. but i pulled the turbo and there's no obvious way to adjust the actuator arm, and the flapper appears totally sealed with everything put together. so I am assuming the boost leak must be elsewhere?

 

if it makes any difference I t'd the boost gauge off the line to the stock turbo gauge in the cluster.