1998 Chevy Lumina Fans Quit Working

1998 Chevy Lumina question.

Cooling fans quit working relays are good fuses are good fans work with direct power they don’t work with the temperature switch unplugged either. Could jump it at the PCM but don’t know where it is located.

Answer: The PCM is located under a cover on the passenger side under the hood. You need a schematic to find out which wires to jump to take the place of the computer. It may not be turning on the relays.

The relays work together with each other, so if one were bad, it will cause the other to not function. You say the fans work when you jump them. Are you supplying the power and ground, or just power? If both, then you need to check the ground side of the fans. That is usually located on the transmission bell housing. The large black wires coming off the fans. Then check to see if you are getting power to the fans from the relays.

There could also be broken wires in the harness that runs to the fuse/relay center, or even an internal problem in there. A schematic is really going to be needed to check the circuits properly.

Chevy Cobalt Cooling Fans

I have a 2009 Chevy Cobalt my cooling fan stopped working. It doesn’t spin or sound like it even wants to. I’ve replaced the relay, fuse and bought new cooling fan and still nothing. What else can it possibly be?

Answer: First, you need to be sure the coolant temperature sensor is functioning properly and the PCM sees that the fans needs to come on. You could also turn on the A/C and see if it works. These are two different requests but can give an indication of which way to go with diagnosis. Instead of just replacing parts, get a test light and when you think the fan should be on, test for power and ground at the fan. If one is missing, check that circuit. The PCM controls the ground circuit. IF you have power in then possibly a bad ground wire to the frame.

Chevy Lumina Jerking

My 2005 Lumina v6 3.8 jerks while it is parked and still the engine is on. It feels like misfiring, when its running its fine, only the problem is when the car stops on signals or parked while the engine is start, kindly advise.

Answer: It could seem to be running fine to you, but actually could be misfiring just slightly enough for you to feel a vibration. Multiple things can cause this, such as a bad spark plug, or ignition wire, coil, fuel injector, etc. Otherwise, bad motor mounts can transmit vibration when they wear out, as well as something is out of round, or out of balance, like a harmonic balancer, torque converter, and the like. I’d recommend getting this checked out by a professional. They can use a machine to see if it is actually misfiring or the vibration is coming from somewhere else.