tachometer not working

Free2drive! · Post by **Free2drive!** » 11 Feb 2011, 07:44

Still working on the tacho' but I thought I'd pop up a photo of the cluster. This is what is displayed following the test procedure on A7 posted by ozark Lee... The tach shows 2300rpm no matter what speed I am doing even at idle.

btw what do you think of the wooden steering wheel?

Matt
94 855 turbo

Post by **rspi** » 26 Apr 2012, 08:26

This is the first turbo with a VDO cluster that did not have a temp ambient gauge. I'm going to do this test on my cluster to see if it helps me figure out what's going on with my temp gauge.

Post by **rspi** » 26 Apr 2012, 22:14

Well, my cluster tested dead on what it was suppose to do. It was funny seeing the odo click the 0.5 mile.

michonsjm · Post by **michonsjm** » 19 Oct 2015, 17:08

I know this thread is old but still relevant. I can't get my cluster to go into test mode. Maybe I have a different type cluster? 1995 850 wagon, non-turbo.

Post by **Ozark Lee** » 19 Oct 2015, 20:34

There are two versions of the cluster. The VDO which is pictured above and the Yazaki. The Yazaki has the odometer above the center of the speedometer and I don't believe it has the same diagnostics as does the VDO. It also doesn't have the odometer gear problem that the VDO has.

Most of the US cars seemed to have the VDO but not all of them and I don't know that there is any rhyme or reason as to why some were different other than perhaps supply chain issues.

...Lee

michonsjm · Post by **michonsjm** » 21 Oct 2015, 06:51

It looks like I have the VDO based on your description. Do not have the turbo though. A-7 pin does not do anything and never has for me. Cannot get it to respond (no light or codes). A-2 and others do work. Wondering what else to try.

Post by **Ozark Lee** » 21 Oct 2015, 07:21

Is there any chance that the instrument cluster got swapped at some point? There are some other issues that arise along with a swap but the '96 and later had serial data lines that are used through the OBD-II port. Your '95 may or may not have OBD-II as well. Most of the turbos did have both as did some of the N/A cars.

...Lee

michonsjm · Post by **michonsjm** » 21 Oct 2015, 08:13

Have no idea if it was swapped out. Bought the car used from a dealer (4 years old) but did not have any service records. There is an ODB plug under the coin tray in the console. I've always read codes using the diagnostic plug in the engine compartment but nothing comes up on A-7. Looking up the diagnostic codes reference it states A-7 is Combined Instrument (Trip Computer). I do not have a trip computer. Maybe that is the issue? I just don't have a cluster with all the right electronics? Other than that the only thing I can think of is that the A-7 pin/wire has a broken connection somewhere.

One more thing. To reset the service light there is a button, not electronic reset. Would that be a clue?

Post by **Ozark Lee** » 21 Oct 2015, 16:36

The Yazaki reset the service lamp with the odometer reset button but not the VDO so that might be a clue. If you have OBD-II you can use VOL-FCR with a VAG-COM cable to get to the cluster or you can use and ELM327 cable and a terminal emulator program to send and receive diagnostic codes. The latter version gets a bit deeper into the weeds but you can get more information from it. That said, there is no official instruction set for the ELM327 and most of the work has been done through trial and error discovery. The instructions for a VDO may or may not work with a Yazaki.

More information on the ELM327 is here:

http://jonesrh.info/volvo850/elm327_rea ... leage.html

...Lee

michonsjm · Post by **michonsjm** » 27 Oct 2015, 18:23

Thanks for the info. Confirmed it is Yazaki not VDO. Any clues how to troubleshoot it? Should I use a wiring diagram to see if it is a bad connection first?