94 fan problems

[Ratt643]

Hi all,
I've got a 94 Firebird that the cooling fans will not come on when the engine gets hot. I pulled the relays, checked them and all three are ok. I replaced the PCM and the coolant temp sensor with no luck. When I jump the #1 relay, the large fan comes on but can't get the smaller fan to run. The fans will not run with the a/c running. A/c system has a full charge. I am going to check the fusable links and hotwire the smaller fan tommorrow. Anything else I should check? Thanks

[bradmancue]

I am having the same problems with my 94.I have replace the fan, the temp sensor, even had to put on a new radiator. Old one over heated and cracked the side plastic. It seem that if the temp gets over the 200-210 degree range the fan will not come on. Once you reach thermostat range again it comes on like it should. I am in the process of making a high volume thermostat. You drill (2) holes in it so that you have coolant flow all the time. These holes will be 1/8th inch at 180 degrees apart on the flat area of the thermostat. You have positive flow all the time, just not excessive. This will help get the air out of the block, which can cause serious overheating problems. Do a web search for drill holes in thermostat. There are various thoughts on size and location. You can even find a template. I have seen holes up to ¼” in a friend’s pro-stock dragster. And if you are not happy with the result it only cost $5.00 to buy another thermostat.