coolant fan relay location

[Old Guy With Issues]

OK, I have a 2007 gmc Sierra classic 2500hd with the duramax LBZ. My cooling fan runs full blast all the time. I did some research and found a couple of possibilities. The first thing I want to do is replace the coolant fan relay. I have the part already. How ever, I am unable to get any specific information on where this relay is located. Any help with this issue will be greatly appreciated.

 

[gmduramax]

The fan is belt driven. Maybe the fan clutch has malfunctioned and is stuck on.

 

[Ron Nielson]

The first thing I want to do is replace the coolant fan relay.

There is no coolant fan relay. No electrical connection at all to the fan clutch like in later models. It is purely driven by temperature. You probably need to change the fan clutch itself.

 

[TheBac]

Moved to LBZ section. Yup, replace the fan clutch

 

[2004LB7]

With the engine off, how hard is it to turn the fan by hand?

 

[Bdsankey]

If the truck is struggling to maintain temperature I would at minimum check the fan clutch for resistance and possibly replace it with a Kennedy or Hayden unit as well as a new set of GM thermostats. From what I've seen the GM thermostats seem to be the most stable and run similar average temps (2-3f warmer) to my low temp Mishimoto thermostat set over the course of the same drive in almost identical weather conditions.

 

[Old Guy With Issues]

I appreciate the information. I did replace the fan clutch, the problem still persists. Any other ideas?

 

[Old Guy With Issues]

Also replaced thermostats, and also had them pop checked at the dealership

 

[Bdsankey]

What is your ambient temp? What brand fan clutch? What brand thermostats?

 

[Old Guy With Issues]

What is your ambient temp? What brand fan clutch? What brand thermostats?

temp is around 40 to 50 degrees. Clutch fan and thermostats from dealer

 

[Bdsankey]

What coolant temp is the truck reaching?

 

[Old Guy With Issues]

With the engine off, how hard is it to turn the fan by hand?

Not very hard, some resistance

 

[Old Guy With Issues]

What coolant temp is the truck reaching?

OK, at 50 degrees outside, after starting and warming up for 30 min. temp reads 180 degrees. When I hit the freeway, the temp comes up to operating temp. right below 210 degrees. This is driving on freeway for approx. 15 minutes. When I get off the freeway, temp. lowers back down to a little above180 degrees. If temp outside is above 55 degrees, when warming up, the temp. gets to 180 degrees. When I start driving in town, temp comes up to 210 degrees. When I come to a stop, the temp. stays at 210 degrees.

 

[2004LB7]

How do you know it's running full blast? Does it sound like it's roaring. Typically when they fully engage you will definitely hear the difference