So, I just replaced the electric fan with a used unit. The old original fan seized up (literally started burning up while driving down the road). The used fan was bench tested by me prior to installing, it ran perfectly. The fan swap was plug and play. Unplug old, plug in new. Well, not that easy for anyone who needs to tackle the job. Had to pull the grill, headlights, etc...

Now, the fan is not switching on! Should the fan come on as soon as the AC is switched on (with compressor running)? My ultra gauge temps hit over 208 yesterday at idle 90 degree ambient (never seen that before; 180 stat coolant levels on the money) w/ AC on and electric fan never kicked in. My original fan seemed to run as soon as AC switched on. What gives?

Do you think the old fan took out the Fuse or relay? Away from the truck for the weekend will check them later but wanted to get a feeler of items to inspect.

 

The fan comes on at 212 degrees and or when the a/c compressor hits max head pressure.
Do you have and fault codes, if so what are the numbers?

 

Max head pressure. That's what I'm looking for. Thanks Mile. I'll first check fuses/relay then throw a set of gauges on the system and check for proper charges. I may be low on charge, I doubt it but worth checking out if the fuses are good.

 

Old fan motor would have taken the fuse with it when it siezed.

Spec page says on at 212F, off at 202F; or

When AC on, AND slower than 50 mph and AND ambient temp above 82F it should be on, above 62.5 mph or below 77F outside temp it should switch off. Might not need to wait until high head pressure is reached in all conditions.

So you could be driving 65 mph, 206F on Ultra gauge, AC on, and the fan should be off.

 

Thanks for the help, as always. F5 (40A) under hood fuse box was open. Replaced all is "cool" again.

 

uh oh, my fan is not kicking on. it should, by these parameters. it spins freely and fuse is good. Yet, while sitting at idle with ac on..... nothing. any ideas? should I just replace it?

 

So is there a fuse and a relay to check on this, i replaced the fuse that was blown..trying to determine if my fan is toast Where is the relay locatd.

Thanks advance

 

Yes, if the fan seizes then generally the fuse will blow too.

It's 40 amp from memory in the fuse box under the bonnet/hood in the engine bay.
Cheers, Jerry

 

Double check to make sure the plug for the fan is fully seated (it is located on the passenger side directly on the electric fan body). if that checks out look at the fuse for the AC it's located under the hood in the fuse box. I believe it's F5 and is a 40Amp fuse.

Have the truck running w/ the AC on. Touch the metal circular disc on the electric fan (be careful it may be really hot). If it is real hot it is seized.

 

It can be seized, and the "locked rotor amps" drain has already blown fuse, and motor will then be cool. So a cool fan motor does not always mean a good fan motor. Blown fuse would just about 90% of the time be the fan motor.. Fan should spin easily with a butter knife.