2G 1998 Eclipse rad fans won’t turn on without AC on

[Jacobie]

If I have the AC on, the left side fan will turn on, but the right side won’t come on no matter what. I already replaced the coolant temp sensor and tested the gage sensor, they’re both good. The relays and fuses are all good. I do seem to be missing the top left relay that says (Rad fan HI) or something like that. But there’s not even any wiring to the back of the connector for that relay. Any suggestions?

 

[Jacobie]

If I have the AC on, the left side fan will turn on, but the right side won’t come on no matter what. I already replaced the coolant temp sensor and tested the gage sensor, they’re both good. The relays and fuses are all good. I do seem to be missing the top left relay that says (Rad fan HI) or something like that. But there’s not even any wiring to the back of the connector for that relay. Any suggestions?

It’s a 98 eclipse with the NA 2.0 and 5 speed, completely stock

 

[chrysler kid]

Did you get out a volt meter and test for 12v at the connector on the fan to verify that it is receiving power?

Also fan hi-3 is only used on automatic cars, triggers both fans to run at the same time if the car gets over temp without the ac in

Most likely the fan motor went bad, but you need to verify that the connector is receiving 12v to power on, or send 12v to it to power on manually

 

[Jacobie]

Did you get out a volt meter and test for 12v at the connector on the fan to verify that it is receiving power?

Also fan hi-3 is only used on automatic cars, triggers both fans to run at the same time if the car gets over temp without the ac in

Most likely the fan motor went bad, but you need to verify that the connector is receiving 12v to power on, or send 12v to it to power on manually

The fan motor was bad. I ran 12b straight to it and it didn’t spin. I replaced the fan and did the same test that it worked and it spun perfectly. It’s like the ECU isn’t turning it on. There’s no power to the connector. But there is power to the relay.

 

[Jacobie]

The fan motor was bad. I ran 12b straight to it and it didn’t spin. I replaced the fan and did the same test that it worked and it spun perfectly. It’s like the ECU isn’t turning it on. There’s no power to the connector. But there is power to the relay.

*12v

 

[chrysler kid]

Alright I did search but couldnt find any spare info on a 2gnt that gives me further wiring detail

The 420a only has a coolant temperature sensor on the radiator neck, then the ecu trips the relay to send power to the fans

Is the car over heating at all? Sometimes it can take a really long time for the fan command to be sent to turn on. My gst took about 15minutes of idling to actually get up to temp to burp the system and command the fan to turn on

 

[97egl]

The fan motor was bad. I ran 12b straight to it and it didn’t spin. I replaced the fan and did the same test that it worked and it spun perfectly. It’s like the ECU isn’t turning it on. There’s no power to the connector. But there is power to the relay.

When you are testing for power at the relay are you getting 12v on 3 of the wires or just 12v on one of them? The relay will always have 12v on the input side but until the computer closes the coil side of the relay you won't have 12v output. Try grounding the relay coil and see if you get 12v output and if the fan starts.

Found a wiring diagram. It's not the greatest but better than nothing. It is for a 97 so may be slight differences

https://www.2carpros.com/images/question_images/7165/original.jpg

This is the online thread the diagram came from.

My Radiator Fans Do Not Work: My Radiator Fans Do Not Work. They ...

My radiator fans do not work. They are functional, I have jumped them straight to the battery. I have replaced all fuses but with no success. Reply 1...

www.2carpros.com

 

[Jacobie]

Alright I did search but couldnt find any spare info on a 2gnt that gives me further wiring detail

The 420a only has a coolant temperature sensor on the radiator neck, then the ecu trips the relay to send power to the fans

Is the car over heating at all? Sometimes it can take a really long time for the fan command to be sent to turn on. My gst took about 15minutes of idling to actually get up to temp to burp the system and command the fan to turn on

It did overheat the day that I installed the fan, but since then it’s been working perfectly. Maybe I just didn’t have the connector plugged all the way in. But it’s fixed now! Thanks for the help.

 

[Jacobie]

When you are testing for power at the relay are you getting 12v on 3 of the wires or just 12v on one of them? The relay will always have 12v on the input side but until the computer closes the coil side of the relay you won't have 12v output. Try grounding the relay coil and see if you get 12v output and if the fan starts.

Found a wiring diagram. It's not the greatest but better than nothing. It is for a 97 so may be slight differences

https://www.2carpros.com/images/question_images/7165/original.jpg

This is the online thread the diagram came from.

My Radiator Fans Do Not Work: My Radiator Fans Do Not Work. They ...

My radiator fans do not work. They are functional, I have jumped them straight to the battery. I have replaced all fuses but with no success. Reply 1...

www.2carpros.com

The problem was the fan motor on my old fan. I’m not sure why the new fan wouldn’t come on the first night after install. But I started it the next morning and it turned the fan on for a bit as soon is it hit operating temp. Thanks for helping tho!