My freinds '93 camry cooling fans will not come on when engine has run up to normal temp.
they do come on with a/c. Put new temp switch in rad. , still the same.
both fans come on when swith is disconnected at plug at top /right side of radiator.
what else would cause fans to not run at temp...?

 

Coolant not hot enough. Is the engine overheating?

 

After I put new fan switch in(Bottom of Rad) we re-filled w/antifreeze mix and ran for 20 minutes...we could see collant moving at filler neck so we capped it and ran untill gauge showed near half way....still no fan...plenty hot enough.

 

Gauge at half is normal. Fans will usually not come on when moving as enough air flows through the rad to cool. You could run the car til gauge half way then park and idle for a while. You'll probably hear fans come on after a short bit. I'd only worry if gauge went above half and fans did not start. Check your fluid level after refilling and runningthen parking to cool.

 

Fans come on at around 199F. If worried place a thermometer into the radiator fill point then start the car and let it warm up.

 

Sorry...should have been more clear...Car WAS sitting at idle...not moving.
Left rad cap (new) off untill saw coolant moving and steam rising from filler neck and gauge was climbing....Owner of car said fans normally came on when gauge was just under half...
now they do not. I'll try again with thermometer.....fans DO run when A/C is turned on or switch unplugged.

 

If the the car is overheating and a properly functioning fan circuit is not turning on the fans then I would look at rad and/or water pump. This problem came up on another thread and it turned out to be the rad. If there is not enough flow then the coolant can run too slowly through the rad and coolenough not to actuate the fans, but the coolant in the engine willnot be cooled and the engine will overheat. It may also be that if there is not enough flow through the rad the system may cavitate.Looking at the flow with cap off may show where the problem is but it will be cheaper to replace/recore the rad than change the water pump unless you need to do a timing belt,in which case you would change the pump anyway. How old is the rad?