1998 cadillac deville , cooling fans for rad will not come on and I already replaced the AC comp relay

did you change your thermostats there is one on the motor and on radiator. i have a toyota and was told my motor was shot it was overheating and loosing coolant my prob was water pump and the radiator filler pipe had a pin hole in it. if you do not have water in your oil or oil in the rad then it is probabnly not the head . also if the fin on your radiator are bent you may need too change radiator..Also your radiator fan may not be working, you can hook direct or buy a new fan relay sensor that plugs in at the bottom of raiator, you can check this by getting motor hot and see if fan kicks on

There three main parts to the ac system. comp, dyer and lines. when you replaced them you used and made sure the all orings where in? charged and added dye to check for leaks? insure that the comp is kicking on and that the fan is working?
let me know
M.Woodring

check the rad and cooling fan on motor also check fan relays
make sure rad colling fins are clean if all this check out o.k.
cylinder heads may be plugged up try reverse flush if it dont help
head gaskets or heads

There are three cooling fan relays in the fuse block under the hood.




The fan relays above are numbered 37,39 and 40

Relay 37 is RH fan
Relays 39 and 40 are LH fan.


You can check if your fans are working by switching on the air con.
Are you having overheating problems?

Regards.

If for the heater it is a blower module on top of the evaporator core housing. If for the cooling fans it is inside the front fender behind the headlights. That is a module also tice the size of a normal fist

Are you sure that you don't mean the cooling fan control module? It should be located up front next to the cooling fan. It is square shaped and has a long square shaped plug going into it. Reads the temperature of the coolant and passes the information to the engine control computer (ECC). The ECC receives analog information and signals the cooling fan switch to cycle the cooling fan on or off, as required.

I HAVE A 1998 CADILLAC DEVILLE,THE AC BLOWER MOTOR GETS HOT AND TURN OFF AND WONT TURN BACK ON UNTIL IT COOL OFF, WHAT IS THIS PROBLEM?

check for air in system(cooling system) also check to see if cooling fans on radiator come on when car reaches about 225-230degrees, if not check relays and fans to see if they ar good if so see if both of them work (they should) if they both come on see if they go off if they dont ever go off then the engine is not cooling down have a tech. check it out ,could be a blown head gasket or worse

The cooling fans will not come on until 225 degrees. Normal temp is around 199-215. Sitting still in traffic most will inch up around 220 or so. When you turn ac on it turns the fans on and may cool down engine, Check fan operation.