96 850 Turbo Wagon Mechanic's Challenge

[FlipIt]

After some testing I found that the fuel pressure was low again. I determined that the series resistance was high so I pulled the pump and eliminated two of the four mechanical electrical connectors. I ran the engine with a vacuum/boost gauge connected to the engine oil dipstick. From engine cold start to fully warmed the crankcase remained at atmospheric pressure. I also checked the manifold vacuum. The vacuum is a steady 16.5 in. Hg at idle. The vacuum changes briefly to around 13 in. Hg when accelerating and to about 20 in. Hg when decelerating which seems normal.

I need some help correcting the VSS fault. I measured the sensor resistance to be 422 ohms. I read somewhere that the resistance should be from 200 to 400 ohms. Since I don't have a 1996 wiring diagram I traced the wires YEL/GRN and GRN/YEL thru the wiring harness. I was surprised they don't go thru the 26 pin transaxle connector. Nor do they connect to either the TCM or ECM. Instead, they go to a two row connector in the TCM/ECM box that is laying under the mounted TCM and ECM connectors. From there they leave the box in a harness that is attached to the passenger side fender well and then into the firewall. My 1995 wiring diagram has a note that YEL/GRN and GRN/YEL wires go to the speedometer for 1996. The fault (P0500) appears after about one mile of driving whether the VSS is connected or not. The speedometer works but the odometer and trip odometer do not increment. I've read on the forum that the odometer frequently fails after 100,000 miles. Is there a cable from the transaxle that drives it? I haven't been able to locate one coming from the transaxle. I noticed a two wire electrical connector aft and below the VSS but will have to raise the vehicle again to access it. I don't know what it is for.

I'm having trouble removing the VSS. I have the mounting stud/bolt out but can't get any leverage to pry the sensor out. I may raise the vehicle and monitor the VSS output voltage with the vehicle in drive. It's probably a pulsed waveform that may register as AC voltage on a multimeter.

[FlipIt]

With Ozark Lee's help via PM I was able to remove the left and center vent outlets. On the models with the wood grain trim the left and center vents have no removable enclosure. Instead, the horizontal pivots are just held in place by friction and pull straight out. I pulled mine out with a paint can lid opener.

Following instructions on the forum I removed the dash upper trim panel with air bag and the instrument cluster. The leather trim has pulled away from the air bag corners and part of the main dash and looks bad. The trip and main odometer in the instrument cluster does not increment. I will attempt to repair both using guidance from the forum.

[precopster]

This post is a great resource for somebody wanting to resurrect pretty much any 850 turbo or n/a. How did you go with the odometer repair?

[FlipIt]

My wife reminded me of my annual spring yard duties so progress the last month has been slow. I purchased a 1/4 inch diameter 15 tooth plastic gear for the odometer. It cost me $11.50 with free shipping. I installed the gear and manually incremented the odometer to add the miles I've driven since purchasing the wagon. I installed the gear and reassembled the instrument cluster. I tested all of the warning and cluster lights with an ohmmeter and replaced all of the burned out bulb assemblies. I removed the SERVICE bulb since it can only be reset by an authorized Volvo repair shop. I installed the cluster in the vehicle as shown below.

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I was able to remove the passenger air bag without deploying it. I separated the air bag cover from the dash. The photos below show the unsightly bulges in the main section of the upper dash.

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When I examined the underside of the dash I found numerous splits in the plastic. I glued the splits back together with superglue and then reinforced them with aluminum flashing stock as shown below.

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This was a tedious and time consuming process.

[FlipIt]

Next I used two part epoxy to glue the leather bulges to the plastic form as shown below.

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Even though I waited 24 hours before removing the clamps the glue did not hold to the rubber like substance that is bonded to the underside of the leather. Instead of trying a different glue and chancing it coming loose I decided to "sew" the leather to the plastic. I used 24 gauge galvanized steel solid wire as my "thread". I used my electric drill and a 3/64 inch drill to make a hole for every "stitch". The results are shown below.

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I doubt the leather will ever separate from the plastic again. The two photos below show how the shrinking leather pulled away from the airbag cover plastic frame.

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A large section of the plastic was broken completely off on one end and there were cracks on the other end. It was necessary to reinforce the plastic with metal flashing as shown below.

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Even though I tried an adhesive advertised to work on leather and plastic and let it dry for 48 hours the leather began separating from the plastic within two hours after removing the clamps. So I reverted to sewing the leather to the plastic with metal thread as shown below.

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Because the leather had shrunk when I reinstalled the airbag cover into the upper section of the dash there was a gap on the left side as shown below.

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Also, the stitches at the top were more visable than I had planned. So I used two different gauges of wire with black insulation to fill the gaps.

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I attached the wire with adhesive only applied to the dash and not the airbag cover so it would not interfere with the airbag deployment. It's not perfect but I've spent way more time than I planned on this particular task so it will have to be good enough.

[SimLyons]

You have incredible commitment to this job along with the patience of Job. And I commend your wife's patience, too. I have learned more about my 850R through your amazing posting than I have from my (difficult) shop manual. Thank you!

[Red-Arrow]

You know that you could have just replace the material on the dash for a few bucks?