need help!!! cant figure out

[laserstang21]

every once in awhile my car will act up. i have a 2000 gt. my problem is wen temp gets to about half and i run wen i get to about 3500 it will act like its not pullin any more. any help is greatly appreciated. i noticed wen the temp dropped a lil it acted right so would putting a switch to my fan b good?

 

[mustang90]

I would change out the thermostat first. Then, if you have or buy a SCT tuner you can change the temperature setting in the computer as to when you want the fans to come on. This is definetly a better alternative than a switch style.