Instrument Cluster Failure

Lolvolol · Post by **Lolvolol** » 26 Sep 2019, 19:15

Buckle up, this might take a minute to explain. I just bought a 97 Volvo 850 turbo t5 from a not so trustworthy character about a month ago now, among numerous other issues the speedo, tach, fuel gauge and temp gauge all stopped working suddenly after not driving it for a few days (the odo and trip were broken upon purchase already), and now the ABS light is off (it was on while the gauges were working) and the transmission arrow light was on, and then it briefly turned off and then back on during all of this. The engine is throwing: P0172 bank 1 system too rich, and P0500 Vehicle speed sensor A. I tried switching out fuse 35 with a new one and it worked for about five minutes, went through a bunch of different fuses and all of them looked and tested fine but none of them gave me any success, but the sunroof is working fine (which is apart of fuse 35) so it can’t be a fuse issue. I tried taking the cluster out and examining everything, and nothing APPEARED to be damaged, all of the soldering and wires looked just about new. Tried jiggling the key, no success, nor have I had any problems out of the ignition. So now I’m just scratching my head, any advice?

Post by **jreed** » 27 Sep 2019, 05:31

It might be a good idea to check the connector at the ABS control module and the connectors going into the back of the instrument cluster. If they're loose, corroded or damaged they could cause the gauges to stop working.

Lolvolol · Post by **Lolvolol** » 27 Sep 2019, 06:42

jreed wrote: ↑27 Sep 2019, 05:31 It might be a good idea to check the connector at the ABS control module and the connectors going into the back of the instrument cluster. If they're loose, corroded or damaged they could cause the gauges to stop working.

I just noticed something that I overlooked apparently, on the instrument cluster circuit board there appears to be an asymmetrical brown caramel-ish glaze over two medium sized sections of the board. Almost like someone spilled coffee on the thing. I can post pics after work. Could this mean a dead cluster, or is there ways to clean this?

Post by **abscate** » 27 Sep 2019, 09:41

That could be a coating from stock if it is hard and set like an epoxy.

hard to imagine getting food into the dash cluster

Lolvolol · Post by **Lolvolol** » 27 Sep 2019, 10:23

Could be I suppose, but from looking at other pictures I don’t see any with this type of coating on it. I’ll post pictures later

Lolvolol · Post by **Lolvolol** » 27 Sep 2019, 18:49

jreed wrote: ↑27 Sep 2019, 05:31 It might be a good idea to check the connector at the ABS control module and the connectors going into the back of the instrument cluster. If they're loose, corroded or damaged they could cause the gauges to stop working.

Something else I just noticed is that my clock is staying on constantly now, and the clock is the only thing that works other than the boost gauge. It’s odd to me that the clock will appear, but the info screens will not.

Post by **Eddystone** » 27 Sep 2019, 21:30

I have a 1993 940 that had a wonky fuel gauge that was intermittent, and things went downhill from there. I pulled the instrument cluster and resoldered (heated and added a bit of new electronics solder) all of the connections. Everything started working again. The heat/cool cycle and hidden corrosion (tarnish, really) eventually cause cracks and make solder joints that look good actually non-conductive. For anyone with electronics experience, this whole job takes about 15 minutes.

The caramel color might be electrolytic capacitors that have leaked and failed. These capacitors look like little cylinders. Generally speaking (all applications) they often fail simply due to age.

Your problem may be due to something completely different.

Post by **ZionXIX** » 27 Sep 2019, 21:33

Eddystone wrote: ↑27 Sep 2019, 21:30

I fixed a 4runner dash clock that way, best 5 min ever.

Lolvolol · Post by **Lolvolol** » 27 Sep 2019, 22:50

Eddystone wrote: ↑27 Sep 2019, 21:30 I have a 1993 940 that had a wonky fuel gauge that was intermittent, and things went downhill from there. I pulled the instrument cluster and resoldered (heated and added a bit of new electronics solder) all of the connections. Everything started working again. The heat/cool cycle and hidden corrosion (tarnish, really) eventually cause cracks and make solder joints that look good actually non-conductive. For anyone with electronics experience, this whole job takes about 15 minutes.

The caramel color might be electrolytic capacitors that have leaked and failed. These capacitors look like little cylinders. Generally speaking (all applications) they often fail simply due to age.

Your problem may be due to something completely different.

Alright well I’ll see if I still remember anything from my computer hardware engineering days (it’s been a hot minute LOL) and I’ll pull the cluster again tomorrow and see what I can do. Although the size and color of the glaze didn’t resemble a leaking capacitors too much. If it really is the circuit board, and I’m not able to repair it myself I’ll at LEAST be relieved to know which direction to go in next. Will update

Post by **misha** » 28 Sep 2019, 01:43

Next step will be a used cluster from a junkyard.
You will need one from '96 or '97 T5 since '95 and older could be different.
Try Erie-Volvo since you are in the U.S.i heard that they are the best.