Wrong fan clutch

Discussion in 'Classic Mustang Specific Tech' started by mhjo, Aug 18, 2009.

  1. I ripped off the el fan and got a clutch fan w. a huge fan shroud. Yes, it cools like hell, but I wonder if there is something wrong with the clutch/wrong clutch.

    What I asked for was a thermal clutch. However, the fan I got and installed engages all the time, and engine temp gauge only climbs to 1/3 (1/2 max when standing still in traffic-jam). I also get a real wind through the under dash air duct !

    Is the clutch "stuck", or have I got a non-thermal clutch by mistake? The part no. is 8A616-1 and origins from NPD.
  2. I did this years ago to my '66 Coupe. I checked NPD. This is a thermo style fan clutch. These were originally designed to help save fuel by allowing the fan to slip so the engine didn't have to drive the fan constantly like the "fixed" 4-blade standard non-A/C fan. When the thermal sensor senses a preset temp from the radiator, it cranks down on the shaft and forces the fan to run at engine speed until the temp drops. Then it is returned to it's freewheeling state again.

    On mine, I removed the 4-blade "stocker" and installed an OEM re-pop shroud, a 7 blade A/C fan with a new centrifical style clutch. Worked wonderfully.

  3. Yes, but the fan is blowing constantly! - and temp does not rise to normal - it has to be a non-thermal or broken I think...
  4. If there is an exposed bimetallic spring on the front, it's thermal. If it's smooth, it's not.

    You could put the biggest fan in the world on there and it should still heat normally. BTW, according to the owner's manual, you gauge is reading normally. Might be nice to have actual numbers, though.
  5. I'll check the spring. However, the fan blows max from the very minute I start the car, and it just keeps on going. Takes 30 min to reach 1/3 temp. Can't even have the underdash vent open any longer because of the EL Ninja wind blowing in..
  6. Question. I don't understand the rush of air from under the dash. Is your heating system fan running wide open all the time?

    A breeze from the engines cooling fan should not be felt from under the dash. Unless there is a large hole in your firewall or cowl panel.


  7. a lot of times a new fan clutch takes a while to "break in" so to speak. it has to go through a few heat cycles and it will eventually loosen up some.
  8. Your thermostat is what controls the water temperature in the engine. The thermostat is missing or defective.
  9. Thermostat is ok. This underheating issue occurred when I changed fan.

    When it comes to "breking in", I have driven 200 miles with it already..
  10. Something is wrong with your thermostat. You should be able to put a hurricane fan in front of the car and not "underheat". Really.

    The one on the left shows the thermal spring.