I have a 89 cherokee Laredo 4.0. The electric fan is not coming on sitting at idle (temp. higher than 220). Replaced the e-fan switch in radiator, relay on the fender, check the diode (good). Replaced e-fan and t-stat. E-fan will run with defroster on and or air condition on.

I lost coolant changing temp. fan switch and t-stat.

It is a closed radiator system (no cap on radiator). Book says to leave cap off bottle and run engine till t-stat opens and it will take in the antifreeze, but it doesn't seem to (even after a half hour). When I turn off the engine to cool and replace coolant, bottle over flows loosing half the bottle. There is no way the system is full. Also did what the book says about squeezing the top radiator hose to get rid of the air and that seems to work. Tried to check for cracks and head gasket problems (brought engine up to higher rpms) coolant in bottle stays the same, but when I let the rpms go down again the bottle over flows with cap off. Top and bottom radiator hoses hot, radiator hot, and heater hoses hot. Oh!~oil is ok also. Took electrical harness a part and doesn't seem to be any burnt wires or problems. Is there a fuse some where under the hood to run e-fan (not when on defrost or air condition-good)?

Thanks!~jretzky