Coolant fans do not work

47,000 MILES • 5.7L • V8 • RWD • AUTOMATIC
Avatar
T-SMITH
  • MEMBER
  • 18 POSTS
My car has two fan set up the A/C fan works but the other one will not turn on. I changes the relay and changes the sensors for them. It is not the fan motor because i took the engine coolant fan switch off and grounded it out and the fans kicked on. I tested the sensor and it works. I do not know how hot it has to get but I got a blow torch on the tip of it and I checked it with a ohmmeter and it works good. But, it will not come on when it is supposed to.
Aug 1, 2017 at 2:28 PM
Advertisement
Avatar
STRAILER
  • ✓Experienced Mechanic
  • 55,583 POSTS
Hello,

It looks like you have a power issue, Here are some guides that will help you do some testing and a wiring diagram (below) to help you.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

and

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Please run some tests and get back to us we are interested to see what it is.

Cheers, Ken
Aug 3, 2017 at 5:24 AM
Avatar
T-SMITH
  • MEMBER
  • 18 POSTS
It's not the relay the fuses are intact and the wires that turn the fan on are good and the wires that go to the sensor that turns the fan on is good I've changed the sensor and it still does the same thing
Aug 4, 2017 at 12:33 PM
Avatar
STRAILER
  • ✓Experienced Mechanic
  • 55,583 POSTS
It sounds like the ECM has gone bad which controls the fan. Here is its location (below)

Please let us know what you find.

Cheers, Ken
Aug 5, 2017 at 12:05 PM
Avatar
T-SMITH
  • MEMBER
  • 18 POSTS
I got the temp switch from NAPA do you think they gave me the wrong one because there is some that has deferent temp setting like the one I got was supposed to be 220F but they probably gave me one that's higher
Aug 5, 2017 at 12:12 PM
Avatar
STRAILER
  • ✓Experienced Mechanic
  • 55,583 POSTS
That could be, I would try one from GM - AC Delco to see if that works better.
Aug 7, 2017 at 3:21 AM
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Frequently Asked Problems for This Vehicle