The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support Kiggly Racing
Please Support Fuel Injector Clinic

1G Is this the radiator thermo sensor connector?

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

XC92

Proven Member
1,571
358
Jul 22, 2020
Queens, New_York
My engine recently overheated and burst the oil cooler hose. I've since replaced it, but I'm concerned that the reason the engine overheated was because the radiator fan didn't come on like it was supposed to after the coolant reached the threshold temp. I tested the fans and relays and they're all working fine.

I then tested what I think but am not sure is the radiator thermo sensor connector, by disconnecting it from the wiring harness just in front of the air filter, then shorting the harness connector with the key in the ignition all the way clockwise but with the engine off, and the fan didn't come on like it was supposed to.

Either the connector is bad or there's a break in the wiring somewhere, or I tested the wrong connector. Is this it:

You must be logged in to view this image or video.


I'm referring to the left and center connectors. The left one connects to the wiring harness and the center one to the thermo sensor. Are these the right ones, or is it the one on the right, or a completely different one that can only be gotten to from under the radiator?

Also, does the fusebox on the right side on the engine bay near the battery look ok?

You must be logged in to view this image or video.
 
So, way off. Do I therefore have to get under the radiator to get at and test the thermo sensor connector?
 
So, way off. Do I therefore have to get under the radiator to get at and test the thermo sensor connector?
Yes. It’s right next to the lower rad hose
 
I haven't driven the car since the hose broke, not until I can confirm that the fans are working properly and will turn on when they're supposed to. I didn't go through the trouble of doing all the work I've done since last summer (and didn't subject everyone here to my endless and annoying questions) just to kill the engine because of a bad switch I was too lazy to check.
 
Haynes are very "generic". I love my FSM's.
Try turning on the A/C and see if they both come on.
 
A/C isn't working. The blower comes on but no cold air. Belt is turning compressor.

I recently yanked an old security system that I haven't used in years. I wonder if that messed up some of the electronics? The radio's no longer putting out sound and the auto door lock's acting funny.
 
I haven't driven the car since the hose broke, not until I can confirm that the fans are working properly and will turn on when they're supposed to. I didn't go through the trouble of doing all the work I've done since last summer (and didn't subject everyone here to my endless and annoying questions) just to kill the engine because of a bad switch I was too lazy to check.
You wont kill it. Just let it idle up to temp and if it doesn't ever turn on (before it gets too hot) then it aint workin.
 
Do people install dash failsafe switches to manually turn on the fan in case the sensor switch isn't working properly, until they can replace it?
 
Haynes are very "generic". I love my FSM's.
Try turning on the A/C and see if they both come on.
Turning the blower on with the ac button only turns on the d/s fan. I think you can jump the wires to the thermostat switch and this should turn the p/s fan on.
 
Turning the blower on with the ac button only turns on the d/s fan. I think you can jump the wires to the thermostat switch and this should turn the p/s fan on.
Is the condenser fan less effective at cooling the radiator than the radiator fan?
 
Ok, just ran a check and everything appears to be fine. Turns out that the radiator fan connector has 4 leads, 2 for the fan motor and 2 coming from the thermo sensor switch.

So I disconnected it, bridged the fan leads with alligators (from connector to connector), then bridged the switch leads on the harness connector (with the ignition all the way right w/o the car running), and the radiator fan came on.

The condenser fan did not, but, oddly, as soon as I unbridged the switch leads, it briefly came on. Not sure why but it probably doesn't matter as I separately tested it the other day and it works fine.

I then ran the car long enough to get the coolant hot enough to activate the sensor switch and turn on the fan(s).

Everything's cool. Literally, almost.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top