95 camaro z28
New thermostat
new optispark
new water pump

I tested my fans and they both turn on when I put a paper clip in the thing under the dash. I vented the system by unsrewing the nipple in the radiator hose and the car overheats. Also the fans wont turn on by themselves and I replaced the old fan relays with brand new ones. Any ideas?

 

If the fans fail to go on by themselves, check the engine temp sensor (not the temp gage sender), and wiring & connectors from sender to PCM. Then from PCM to fan relays (there a 3 of them) Low speed should go on @ 220 & high speed at over 225. Fans should run anytime the AC is on. Also make sure the air dam under the radiator is in place.