speedo error

petek153 · Post by **petek153** » 06 Sep 2011, 18:58

Here's a new one, started my 95 850 today for work as I took off noticed the speedometer climbed slowly to 45mph even though I was only doing maybe 20 then stayed there even though now I was at highway speed 65-70. After I pulled off highway shut car off took awhile but speedometer finally dropped to 0. Restarted car and took off and it worked fine. After work 9 hours later took off did the same 45 mph for awhile but then without stopping it started operating properly.Any ideas whats up with this searched forums but didn't find anything about this issue.

petek153 · Post by **petek153** » 05 Oct 2011, 17:19

update still a problem found that on a 95 850 uses a speedometer sensor on the back of the transmission picked one up FCP was a genuine Volvo installed same problem no mater how fast or slow I go reads about 45mph. When you stop slowly goes down but remains at about 10 mph . Tried pulling computers out and reseating pulled dash apart checked plugs on assembly but all were good. anyone have any ideas ? Checked exposed wiring next step I guess would be to open plastic housings and check wire back to comp.

Post by **Ozark Lee** » 05 Oct 2011, 19:11

Since you changed the VSS my best guess is that the cluster itself is failing. Any codes from port A-7?

...Lee

petek153 · Post by **petek153** » 09 Oct 2011, 12:11

Checked no codes from port A-7 The strange thing is spedo will read on occasion mostly after car is warmed up and then shut off and motor has time to radiate heat in engine compartment, somewhere its like connection is made.
update:
Pulled a instrument panel troubleshooting guide off internet and went out ripped the dash apart to do checks have sensor signal reading up to cluster so now looking like cluster speed is done for so now to find a replacement cluster. Have a 96 cluster tried that but not compatible all kinds of warning lights and flashing arrow so old ones back in and codes cleared. If anyone needs troubleshooting guide for the cluster here's the site: http://www.volvoclub.org.uk/tech/servic ... tPanel.pdf

petek153 · Post by **petek153** » 15 Oct 2011, 17:57

Final update pulled cluster, figured nothing to loose, disassembled and checked circuit board. Found where the cluster plugs into board solder joint was broken feeding speedo needle when it got warm enough must have made connection. Soldered up that joint and a couple others assembled and speedo now works (:

Post by **Matty Moo** » 15 Oct 2011, 19:56

Smart man...good work.