Temp gauge 'inop'

Post by **whilst** » 24 Jun 2017, 14:23

Hi all. Can anyone show me wiring schematic for ECT - Temp gauge?
New Volvo sensor, checks out w/meter.
> Had cluster out for Odo gear fix. Did work for a few days. Now zilch.
What is electron flow to / from gauge?
Thanks, Jeff

Post by **cn90** » 24 Jun 2017, 15:10

Check the connector wiring. This is a spot near the PS Pump bracket, known area of corrosion etc.

Post by **rspi** » 24 Jun 2017, 18:47

I have had those temp gauges go out. Check temp with OBD2 reader live data.

Post by **whilst** » 25 Jun 2017, 08:26

cn90, I cleaned up that connection.
rspi, Robert, actually had a Temp gauge go out? By itself?

Can anyone tell me where voltage comes from/for/to ECT to gauge ?
ECU?
Thanks all.
Jeff. 256K and running better than it ever has! (Except for Trans - Reverse slipping*#@&! anybody ever figure out what exactly causes this?)

Post by **esl_97_850_T5** » 25 Jun 2017, 11:30

Assuming you are talking about Temp Gauge on a 1995 854T:
- download the (primarily 1995) Volvo 850 Service Manual,
- expand it (for ease of individual file access in future),
- open "instrument panel.pdf",
- search for the TEMPERATURE GAUGE TEST section on pgs 8-10 (of 22).

There are several tests there, using the under-the-hood diagnostic connectors, to isolate where the problem is. The last paragraph of that section (ie, just before the TACHOMETER test) is probably the most important one for you.

My guess is that when you reinstalled the COMBI (instrument panel) you didn't hook up the connector thru which the Motronic 4.3 feeds the engine coolant temp values to the COMBI. Or the connector is not seated firmly. Or a wire was inadvertently broken. Or??? I doubt that the Temp Gauge is bad, since the problem didn't manifest until your removal / reinstallation of the COMBI.

Post by **rspi** » 25 Jun 2017, 13:12

whilst wrote: ↑25 Jun 2017, 08:26 rspi, Robert, actually had a Temp gauge go out? By itself?

Jeff. 256K and running better than it ever has! (Except for Trans - Reverse slipping*#@&! anybody ever figure out what exactly causes this?)

Yes, the gauge itself. If you pull the cluster, then take it apart, you can replace the gauges individually.

Also, I did test the cluster with the instructions mentioned above.

Post by **whilst** » 25 Jun 2017, 16:59

'esl' - Thanks! I'll check that out.
'rspi'- Ok.

> How about that "reverse trans prob"? answers? Anyone? Buehler?
> Has to be someone who figured out the fault....
Thanks,Guys.