1993 Volvo 960 Wagon - ABS Light on, Speedometer stopped working, Flashing arrow...
 

Hello all!
I was driving at around 50 mph the other night when all of a sudden the ABS light came on. Immediately after, the speedometer needle dropped all the way down, tried to climb up a few times and ultimately dropped all the way and it hasn't moved since. At the same time, the arrow on the dash started flashing and so did the the lights next to the shifter (W and S) switching back and forth.
I read everything I could about it possibly being a PNP switch but it just doesn't seem like it. The car starts on P and N. The reverse lights work just fine. The car shifts almost the same as before with one difference. After driving for a bit and the car has gone through the gears, once I come to a stop, it will try to take of from the second gear. So the car doesn't switch all the way back to the 1st gear unless I manually switch to R or P and then back to D in which case it starts from 1st again.
I have records showing that the PNP switch was replaced in 2015. I also have records showing that the transmission was routinely maintained (flushed and so on).
Some mechanic told me that the ABS and Speedometer could be the wiring on the back sensor above the differential. I did find that the wires were in bad shape there and I repaired them but replacing them with new wires. That did nothing to fix the problem.
The car has 180k miles.
Thank you all for your help and suggestions!
ilir

Have you checked for self diagnostic codes at the diagnostic port under the hood? Those codes might give you a starting point.

Hi Hoonk. Thanks for the suggestion!
I have not checked the codes but I'm going to a Volvo mechanic on Tuesday to get some readings.
In the meantime, I took the instrument cluster out last night like it was suggested in one of the posts. I don't have the capacitors to replace the old ones with but the cluster looks brand new. No leaks, no rust, nothing suspicious.

You can check for codes yourself, there should be an OBD box under the hood, by the driver's side strut tower, although I don't think the tranny is covered...

As far as the cluster, they all "look" good, what you can do is carefully examine the soldering point for cracks using a magnifier.

Thanks, Lev!
That's what I did with the cluster, I examined every bit of it with under a desk light with a magnifying glass. It really looks brand new. No leaks, no built up corrosion anywhere and no cracks. If I were splitting hairs, I'd say that maybe one or two of the screws needed a slight tightening but that was more me trying to do something after spending all that time taking the cluster out and apart than anything real.

Yesterday, however, I was replacing a windshield washer pump and I disconnected the battery since I had to remove the air box and disconnect the old wires. I replaced the pump, connected everything back up and when I started the car everything was working as normal. Speedometer works, flashing arrow gone, ABS light gone etc. This may just be that I reset the codes by cutting the power source and the problem will eventually come back but right now it's back to where it was last week.

Well, often things work out in mysterious ways! Who knows, may be tightening the screws helped it, I've seen that before. Volvos especially, do fix themselves sometimes...

Yeah, not for too long, unfortunately.
It started with the same problems after a half day of errands around town. The code I'm getting is 2 3 2.
It's a code that directs me to the VSS (speed sensor) but like I mentioned before, I replaced those wires. I talked to another mechanic and he said it's likely some transmission module up front not the speed sensor. I'm a little lost now and I'm going to let him diagnose it.
Thanks for the push in the right direction.