Chrysler Repair: Overheating at slow speeds, coolant leak, radiator fans

Question
1999 300M. After stop and go driving for about 20-25 minutes the gauge shows the car is overheating, as soon as I start driving at faster speeds 45 and up the gauge shows a decrease on temperature back to normal. The decrease on temperature when driving at a faster rate of speed is fast. The air conditioner is only blowing hot air. No coolant leak. Appreciate your help.

Answer
Hi Daniel.
I would first check to see if the radiator fans are running once the temperature gauge starts going up toward hot. They should come on automatically by a sensor of the coolant temperature. If not then check the fan fuses (B-30 amp and E-40 amp) in the box in the engine compartment where there are relays and larger size fuses(next to the radiator overflow bottle and engine dipstick). Those two fuses are needed to operate the fans and the AC compressor via 3 separate relays. Also check fuse 21 in the fuse box under the dash because that one is what powers those relay switch functions. Then if that doesn't show a problem write back with any other observations you can offer about the fans function.
Roland