engine heat sensors?

[towmater]

I just had to replace my heat temp sending switch on my 93 sidekick which is located just underneath the thermostat housing facing twards the front of the vehicle. My question is, there are two more sencors or senders to the left of that one facing the right fender, what are they? The one I assume goes to the computer because it has a couple of wires on it and above that there is another one that almost looks identical to the heat switch that I replaced. Now that one does not have the wire on it, it looks like it has been corroded off, but I can't find the wire? Everything seems to be working okay though so should I worry about that or just forget it? just wondering what it's for?

[deardsy]

Bought a spare motor not long ago, had two water temp senders in the two positions you have mentioned.
As far as I can tell they are the same sender.
If you have a sensor for your gauge and another for the ecu, you'll have no dramas.

[jtgh]

no,
one is only for the dash gauge ( 1 pin)
the 2 pin one is extremely important,
it is called the ECT , and the ECU uses it for all fuel maps.
as it ages they all cause the engine to go richer and make MPG go to heck.

buy a new one ever 15years, hahahah, rockauto.com for $40
the pay back will be amazing. 5min job too.

ECT - ENGINE COOLANT Temperature Sensor, the otherone is a SENDER (guage)

one is crude other is very accurate.

if you want to test it , here is my lab data on a brand new one.
IAT is AIR sensor.

temp-sensors

I popped for a new IAT too,as the replacement was the newer FAST acting type.
it comes closer to measuring AIR temp with out the bad heat soak problems.


my data is for running a custom ECU with factory parts. ( PNP style and reversable , no hacking of car )
just practice for something more challanging.....

[deardsy]

Yeh, sorry. I did mean the two positions other than the two pin sender, hence why I said if you have an ecu sender and a gauge sender, no worries.

Will try to be more accurate next time.

[jtgh]

sorry, i was only trying to help towmater, tune his engine. using my thermal map.