Need alittle help with my GMC Acadia fan problem

[TerryMason]

I broke down and took my wife's 2012 to the shop for some AC work. They replaced everything (compressor, condenser, and others), until there was only the cooling fan left. They also mentioned that I needed a water pump. I decided I could do these two things on my own.

So, I've gotten the water pump and cooling fans in, however the issue is that the fans ever come on. I can get the truck up to temp, and turn the AC on, and the fans don't come one. I put 12v on the old fans - they spun, so I tried hooking them up, with no luck either.

I've checked the two under-hood fuses, and swapped the relays with no luck. When it idles, I can feel the radiator get pretty hot (feel heat coming off)

Any thoughts? Should I have purged the cooling system of air somehow, and the lack of pressure would keep the fans from coming on? All I did was remove water pump, replace, then top off fluid.

 

[JPNinPA]

If the fans work when you bypass. And you verified the relay and fuses. I'd look at the temp sending unit.

Was this issue there before the water pump was changed? Did you burp the system?

Regards,
JPNinPA

Never look down on anybody unless you're helping them up. -Jesse Jackson

 

[TerryMason]

You know, i don't know that the issue was not there before the water pump. This all started because the AC didn't work. The shop did a bunch of work and said "you also need a water pump" - I didn't see any indication that it was leaking, but figured I'd change it anyway.

I changed the water pump, then lowered the car, drove it around the court, then topped off the fluids.

I'm going to do a bit more work on it Wednesday to try and figure out what's up. The worse part is that the fans don't just come on - they are computer controlled, and only come on when the system believes they are needed. From what I've read however, they should always come on when the AC is engaged.

-Thanks for the help.

 

[JPNinPA]

Yes they should(at least one) when AC is called for.


Never look down on anyone unless you are helping them up - Jesse Jackson

 

[TerryMason]

Thanks for the help JPNinPA

For those who follow:
The issue ended up being a dirty ground. Everything looked clean, but the fans were grounded to the body - I took the ground off, cleaned it up and bolted back on. The fans started spinning after that.

 

[JPNinPA]

Thanks for the help JPNinPA

For those who follow:
The issue ended up being a dirty ground. Everything looked clean, but the fans were grounded to the body - I took the ground off, cleaned it up and bolted back on. The fans started spinning after that.

Well glad you got it fixed. Sux that you replaced good fans with new. But it happens.

Re reading i missed the fact you tested the old fans out of the vehicle and put them back in.
I just replaced fans on my old Honda for the Cooling. AC fan worked but cooling didn’t. The first test I came across was to jumper the fan power to be sure it is not the wiring. I did this before removing. I first did power then both power snd ground. Doesn’t help now but if others read.


Never look down on anyone unless you are helping them up - Jesse Jackson

 

[TerryMason]

The fans in this GMC Acadia are frustrating. They come on and go off as they see fit. Sometimes one fan on high and the other off. I can't really find a reason for it, but I've decided that's just how they do. No matter what they take a few minutes of the car being on before they do anything - I think this is one of the main reasons some of my diagnosing was off.