Nissan Cefiro A32 Electrical Problem?

chopssuzi, Jun 4, 1:42am
Hi all, we have a 1997 Nissan Cefiro that has a strange problem. The temp gauge started to fluctuate from normal to off the gauge hot, then you could tap the dash and it would drop down to normal again. Now the gauge just slowly goes from cold to off the gauge hot when we first start and run the car. We initially thought the motor must have been getting hot and replaced the thermostat, as a first step. Now we know the motor is not getting hot, and we have been driving around for a few months like this. We now believe the fault might be electrical. We even replaced the gauge with a brand new one from nissan, and replaced the sensor thing that screws into the engine, still no change. Does anyone have any suggestions what could be wrong!

andrea_w, Jun 4, 1:56am
What sensor did you replace! There are 2 water temp sensors
1 is for the ECU
1 is for the gauge on the instrument cluser

chopssuzi, Jun 4, 2:29am
I think the one I replaced was for the gauge, wasn't aware of one going to the ecu,will that be the one near the temp gauge sensor that has multiple wires off it!

chopssuzi, Jun 4, 2:54am
Just had a look, is the ECU sensor the one with two wires coming from it just behind the gauge sensor! Cheers

andrea_w, Jun 4, 3:01am
I'm not familiar with your engine but if it's like other Nissans of that era then yep, the 2 wire sensor is the one for the ECU. The single wire sensor is for the temp gauge

bigfatmat1, Jun 4, 3:06am
The gauge will read hot when the wire is shorted to ground thus would leave me to believe that since you have replaced both ends ie gauge and sender then the wire is likely to be shorted to ground somewhere, check wiring & connectors.

bigfatmat1, Jun 4, 3:07am
Disconnect the senderand the gauge power up the wire through a test light from the gauge end to see if its shorted to ground

bigfatmat1, Jun 4, 3:10am
If the wiring is ok check power and earth to gauge, compare to readings to the working fuel gauge as this vehicle is very likely to have a voltage stabilizer so its important that both gauges have the same voltage. If still ok remove the 's' screw from dash and see if the gauge operates through your test light. if still no luck post back

chopssuzi, Jun 4, 3:47am
ok, I have replaced the ECU water temp sensor as well now, no change. I will get a mate up during the week with a test light to check wiring etc. Cheers for all the help and ideas guys I will post up our findings