Hi folks, I have an interesting one. My Temp gauge keeps flicking over to full scale deflection (triggering the superb Mason alarm - it was doing this occasionally before I fitted the Mason alarm). Giving the dash a sharp whack on the top seems to cure it - so a dodgy connection on the signal wire, perhaps shorting to earth. Heres the interesting thing. Took the instruments out, connected up the temp gauge with 12V feed, earth and a resistance on the signal wire to give half scale reading. Then tap, tap, tap, jiggle, wiggle, but I could not provoke the gauge to flick over to full. But refitting into the dashboard wiring, and it does it all the time. So, the bad connection cant be in the instrument cluster, but must be in the wiring under the dash somewhere ('cos a good whack sorts it - till the next time). Interestingly, on the connector that supplies the 3 feeds to the gauge (the blue one connector), the earth and the temp signal are separated by a spacer - so no chance of a short there. Im out of ideas, anybody think of anything?
- (#12271) JJT, 22 Jul 04 15:49
Certainly sounds like the signal wire shorting to earth, and if a bash on the dash cures it then it must be nearer there than down by the sender. The signal wire goes through one more set of connectors (IH3 pin 7? over the drivers left knee) before it leaves the dash area. Maybe the wiring's trapped somewhere against the metalwork?
See
http://www.mpvi.net/im/rm289e92/ewd/24inspan.gif
http://www.mpvi.net/im/ewd147f2/90daswir.gif
http://www.mpvi.net/iam/ewd147f2/91daskey.gif
- (#12271) Dave Mason (Sussex), 23 Jul 04 06:16
Excellent Diagrams Dave, Thanks, Ive yet to look for the other connector yet. The problem has got much worse now, this morning I listened to your alarm beeping at me for 20 minutes! My knuckles are bruised from rapping on the dash! Its very disconcerting not knowing what the temps doing. Im starting to suspect the gauge again though, my test set up was feeding it 12V when in reality it gets around 13.5V when wired up in the dash. Im wondering if that may make a difference (heating and expansion of the coils maybe).....
- (#12271) JJT, 26 Jul 04 03:52