my fan is stuck on

**transamdude99** · 02-25-2009, 02:23 PM

so whenever i turn on my car on, my fan turns on immediately. im thinking its a stuck relay or something. is there a way to fix this without taking out my fuse??

**pajeff02** · 02-25-2009, 03:36 PM

Easiest check is to swap out the relay with another of the same style. Just make sure the one you pull for the test is a non-critical circuit. With the other relay in place of your existing fan relay see what happens. If the fan now works normally, you have a relay that is stuck closed.

A standard relay has four prongs and is either "normally open" or "normally closed". The fan relay is usually "normally open" meaning that when the coolant temperature switch (or AC controls) call for the fan, power is supplied to a prong on the relay and it closes the circuit. The actual closed circuit will either be a power supply or ground to the fan motor, depending upon how it is wired -- best guess is that it is a power supply.

The four prongs are generally identified by number. You can pull up a diagram on-line or utilize a test light to probe the connections after pulling the relay to determine their functions. One will be a ground, another switched power, one will either be the power supply or ground to complete the circuit, and the final prong will be connected to the fan motor.

**0rion** · 02-26-2009, 09:31 PM

I would do like pajeff02 said and start with that relay. I'm pretty sure the air pump relay is the same so you could swap that in there.

**transamdude99** · 02-26-2009, 10:57 PM

while im thinking about it, what is normal running temp for these cars?

**95camaroZNC** · 02-26-2009, 11:13 PM

My fans always on with my LT1 i had the computer retuned to kick them both on at 180. This is all after i burned them out replacing my radiator by accident.

**0rion** · 02-27-2009, 04:58 AM

it's been so long I'm having trouble recalling what the stock fan settings are but I *think* the car ran ~210 or so.

**thearborbarber** · 02-27-2009, 07:54 AM

For a 99 camaro the first fan comes on at 226 and off at 219. The second fan on at 234 and off at 227.

**2001NBMZ28** · 02-27-2009, 08:30 AM

My low speed fans will come on temporarily sometimes at startup, I have LEDs wired to my fan switch so can see it. Even if you don't have something to command them on you might find something here: www.gearchatter.com/viewtopic8796.php