81 Sport Coupe

I have 3 coolant sensors on my engine. please correct me if i'm wrong, my understanding is that the 2 prong one in the intake sends information to the ECM to turn on the main fan closest to the engine at 238f.
The sensor on the drivers side has a connector like the knock sensor which turns on the aux. fan before the radiator, when I ground this wire the aux. fan turns on when the ignition is on.
The sender for the fuel gauge is a blade type sensor located on the passenger side closest to the firewall.

xrav22

Not quite
1 drivers side is for your reading in digital
2 intake sensor in froint sends ecm tem for startup temp
3 passenger sensor between 6 and 8 is for aux fan in front I have a 205 (instead od 238)in there now which passed smog and keeps things cooler.
Main fan gets turned on by 1 or 2 not sure which at 228 degrees.
Good Luck
sorry one last edit just because we ground something doesn't mean the ecm is going to unless there is a reason

Cliff Harris

You're both right.

There were variations in the locations of the coolant temperature sensors from year to year.

xrav22

I have an 85 , I should have written that

81 Sport Coupe

Thanks guys, so on an 85 the passenger sensor wire between 6 and 8 when grounded should turn on the aux fan? and this sensor should have the fitting like the knock sensor?

WVZR-1

An original switch would use the single pin "squeeze" like the KS - the wire when grounded should turn on fan IF the relay is properly wired and functioning, key should be in RUN.

This is for an '85 ^^^

In your original post it seems you've mentioned what would be found on an '87 engine and you mention in other threads "replacing an '85 with '87".

xrav22

Mine(85) is original still and it does turn on aux fan.