Running cold?!?

[fredf]

Time for my next stupid question...

Over the last 2 days the water temp gauge has been far lower than normal. On clear roads it used to stay at about 70-75, now it's closer to 60. haven't had a chance to try in traffic yet.
I'm guessing this is because the thermostat is broken. does that sound right?

[Big Al.]

Sounds like the temperature sender is on it's way out.

[fredf]

can i just check before doing anything silly.
there is a single green wire going down behind the dizzy which leads to the sender, and there is a 'spare' sensor at the top of the block. is it possible to just move the wire to the spare sensor?

[david beer]

Oh yes. It has been covered so many times, do we all see the same stuff ?

[GreenV8S]

Does it heat up when you are stopped? If so, that is fully consistent with a failed stat.

[fredf]

GreenV8S said:

Does it heat up when you are stopped? If so, that is fully consistent with a failed stat.

it seems to heat up and cool down as normal, just that the values are all suddenly 15 lower.

[spend]

Clean up the connector to the sensor ?

Dave

[GreenV8S]

ou can use the fans as a sanity check on the gauge. If the fans switch on and off as normal, and the gauge shows 15 deg colder than normal at the time, that's a strong hint that the gauge is lying. In that case I'd start by inspecting the wiring out by the temp sender, locate the calibration resister (I assume it has one) and see if everything is intact. Oh, and have somebody watch the gauge while you wiggle all the wires, hot engine, stopped with the ignition on.

[fredf]

well i've changed to the spare sender and it seems to work, but does anyone know where i can get a heat resistance variably resistor which is suitable so i can calibrate where 90 is?