I have a 1998 GC with a 3.8, both fans do not turn on. I even tried turning on the A/C then tried the Def. and the fans do not come on. I checked the 40A fuse and changed it out with another one, no good. I then checked the fans with a 12V battery, they work. Is there another switch or fuse I missed?

9 of 10 times the fan control relay is the culprit. It's mounted on the frame to the driver's side of the radiator under the air intake box. Follow the harness from the fans and you'll find it. Disconnect it and jumper contacts with the grey and dark green wires. Don't need the key on. The fans should turn on. This checks additional wiring and the fans you've already tested. If all is well change the relay - around $50. On rare occassion the PCM won't supply the required modulated power to the relay. PCM is around $350. $600 at the dealer.

A binding fan bearing can fry a relay. Spin each by hand and make sure they turn freely.

9 of 10 times the fan control relay is the culprit. It's mounted on the frame to the driver's side of the radiator under the air intake box. Follow the harness from the fans and you'll find it. Disconnect it and jumper contacts with the grey and dark green wires. Don't need the key on. The fans should turn on. This checks additional wiring and the fans you've already tested. If all is well change the relay - around $50. On rare occassion the PCM won't supply the required modulated power to the relay. PCM is around $350. $600 at the dealer.

A binding fan bearing can fry a relay. Spin each by hand and make sure they turn freely.
A thanks for the info. I changed out the relay, and the fans now work, thanks again for the help. I will check the fan bearing .

Thanks for giving the fix. Happy to hear all is well.