SOLVED: Engine cooling fan only works when ac or defrost

Detail: It wont come on when the ac and defrost controls are in the off position ive swaped relays checked fuses replaced tempature sensor tested cooling fan it works fine but only comes on when in the ac or defrost position
Detail Question SOLVED: Engine cooling fan only works when ac or defrost

Solution: If engine at long stand still,the engine temperature will rise about 190 degrees the cooling fan suppose to automaticaly turn on when coolant temperature sensor get hot it cause its resistance decrease causing pcm to send power to coolant fan relays and cooling fans, when you turn on AC the cooling fans suppose to turn on to cool down AC CONDENSOR, IF NOT AC WONT WORK COOLING FAN COOLS DOWN REFRIGERANT SO IT CAN RECYCLE THROUGH THE SYSTEM AGAIN.your cooling is suppose to turn on when engine at a sit still if vechicle not moving as coolant temperature rises at a set point the cooling fans will turn on cool down engine.cooling fans dont turn on when you first cold stsrt vechicle unless you have AC SWITCH ON.if cooling fans dont turn on when vechicle at a long stand still or moving along slow traffic.if coolant temperature sensor been replaced and fuses and relays okay have dealership check see if pcm driver circuit working faulty pcm will cause cooling fans not to turn on. , So you are saying the engine will overheat because the radiator fan does not come on ? A mechanic would use a scanner to check the temp sensor and override the computer to check the fan circuit. The computer grounds the fan relay when the fan is needed. , Hi, a 6ya Mechanic can help you resolve that issue over the phone in a minute or two. Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US. click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need. Goodluck! , They are all in the fuse box under the hood the relays dont work in a way where one controls one fan and one controls another fan they run the fans in series for low speed and paralel for high speed. They are numbered 37,39,40 you would have to replace them all to see if that takes care of your problem , remove the cooling fan relay you should have power on the pink and black wire and the solid red wire going to the base for the relay if you do then check then turn the a/c on and check for your ground sigal from the darkgreen and white wire if no ground you have a bad fan control module located on the right side of the engine compartment , Most GMs use a relay package to turn on the fans. That is often controlled through a processor package. Very complicated...if yours is one of them. You will need Mitchell's manual or equal to trace this to see if you have all the signals. , u need to buy the special coolant to your car i have the same car whit the same problem and is cause to the incorrent cooland the cooland to your car is the  DEX-COOL  if u dont find that u need some hit       (silicate-free) 

Latest Searches

By entering you agreed with our Terms of use and Privacy Policy.If you do not agree, please do not use this service or you will face consequences.
This site powered by Express JS, node.js, MongoDBand advanced javascript algorithm include all npm modules
Copyrighted © 2015