make sure that thermostat is not installed upside down. check radiator cap, old one may be worn out
Check the engine thermostat.
Upon Review of the question: THIS ANSWER IS FOR THERMOSTAT TEMPERATURES, NOT AVERAGE RUNNING TEMPERATURE, IF THEY ARE ANY DIFFERENT. 1990s 5th Generation Accords: Open 169-176. Full open: 194. Therefore I believe that the 180-degree thermostats are what you want, but I'm not sure if the stamped-on temperature is opening temperature or running temperature?? 180F ~=83Celcius, so get close to that. 78C = 172F, about the opening temperature.
depending on the model year,between 190 and 220 degrees fahrenheit. Most 305's came with 195 thermostats. If everything is working properly it should run at 195.
normally, a gas engine run at 180 degrees(any),if you no sure check the thermostat opening in degrees. Stock thermostats run at 200-210 degrees which is standard for most vehicles past 1990. However, 180 degree thermostats are available and popular.
If the gauge is reading hot and the car is running normal temperatures, the water temperature sensor needs replaced.
Is you Geo Tracker overheating or the temperature is running almost hot then you need to change you thermostat
The temperature sensor for your cooling fan may need to be changed. The temperature sensor wiring may need to be cleaned or replaced.
Possibilities are: temperature sensor, relay (if it uses one), motor, connector(s). If the fan doesn't turn on when the AC is running, it's probably not the temperature sensor.
Try replacing the radiator fuse relay
You have a problem with the charging system. More than likely the alternator has failed.
Have it replaced.
Cracked.head