Water temperature sensors

[ArthurH 7]

What do each of these three sensors do?

 

[welshpug 1,665]

Blue 2 pin is for the ecu, other 2 are for dashboard

[ArthurH 7]

Thanks Mei, which is temp gauge and which is the warning light?

[welshpug 1,665]

I can never remember which is which offhand, but you'll see they have coloured rings on them, these match the original plugs.

 

Or if you've lost the original connectors you can check with a meter on resistance or continuity test, the switch will only give continuity when the specified temperature is reached (110°c + ?    Will be stamped on it)

 

The sender for the gauge will give a resistance dependent on temperature, same as the blue 2 pin but using earth rather than 2 wires.

[SRDT 185]

Blue for the ECU ( M889 be ) red for the gauge ( M890 rg ) and black (M855 nr ) for the warning light, at least in 1991.

[ArthurH 7]

Thanks Baptise.  Now they are disconnected and both spades, I'm not sure that will help.   I'll measure the resistance when cold as per Mei's suggestion.  However, these are a very useful set of diagrams.

 

[petert 596]

The temp light sensor is either open or closed circuit. It has no resistance.

[pug_ham 244 3 Cars]

From what I remember, the larger of the two sensors is temp warning switch & smaller the temperature sensor.

 

Like Mei says, the rings on the sensors match the plug colour with the original wiring.

 

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