Engine Fan Problem-Ac comp running?
 

Yesterday I replaced my Ac evap. and heater core, well I had to drain the coolant to do so (per. haynes manual) so after all was done I refilled the radiator and topped off the surge tank w/ fresh coolant. Now The ac works fine but my engine temp will never get above 165 pulling a 3000# trailer and the fan is running all the time to the best of my knowledge. I dont know what could have happend but I believe something may be unplugged or something relating to the replacement of the evap. and heater core. Also, I noticed know that my AC compressor runs when my heater control panel is switched to the blend setting it also runs when on the ac and defrost setting which i know is normal but i didnt think that it should run when just blowing air out the vent and floor vent, but the compressor shuts off when you switch to either upper vents only or floor vent setting, but the blend setting is when the compressor kicks on, is this normal? Thanks

My '99 also engages the compressor at the same settings yours does. I think it's normal. The "blend" setting you mention is actually the "outside air A/C" and the setting to the left of it that has the snowflake is the "max A/C" setting where you recirculate the air in the cab. Can't help you on the temp though. Thermostat?

I thought it might be the t-stat but its too weird it started doing this after doing the evap and heater core. I dont understand why my fan runs all the time. With the key off I can freewheel the fan, it has alittle drag but I believe thats normal, right??????

If you mean the viscous clutch fan, it will never stop. It kind of freewheels along. Works like a mini-torque converter. Lets you rev up the engine without revving up the fan so much.