Auxiliary fan - purpose.

[Pinger]

Currently stripping out my air con as it is empty and I don't feel inclined to waste time tracing leaks in a cold climate!
Question I have is - on the front of the AC rad is a fan which I take to be the auxiliary fan. What switches it on? High AC temps or is it there for engine cooling (in which case I need to refit it)?
TIA.

 

[HotWheelsBurban]

Yes I would figure it's an auxiliary pusher fan to help cool the truck under high loads. My trucks didn't have this but l have read that many people on this forum have them on trucks they tow with. Unless the engine never gets up to operating temperature with it, I'd leave it be. Can't hurt to have more airflow into a crowded engine compartment

 

[HotWheelsBurban]

Since yours is a 2500(3/4 ton) maybe the towing package option included it. Both my trucks are half ton, but had the towing package.

 

[Pinger]

Yes I would figure it's an auxiliary pusher fan to help cool the truck under high loads. My trucks didn't have this but l have read that many people on this forum have them on trucks they tow with. Unless the engine never gets up to operating temperature with it, I'd leave it be. Can't hurt to have more airflow into a crowded engine compartment

Cheers for that - back on it goes!
Can hardly believe it but that truck has four radiators and that's not counting the engine oil cooler built into the main rad.

 

[Erik the Awful]

GM built these trucks and tested them at the proving grounds in Mesa, Arizona, where the average high temperature from June through August is 40*C.

 

[Pinger]

Fan is going back on - not a problem as the mounts are on the body. It will just be the thickness of the AC rad away from the main rad - but airflow to the main rad will be improved.

The oil cooler for the trans is the problem now as it was mounted on the (now removed) AC rad.
Why it has a separate rad for the trans I have no idea. The pipes which once connected the trans to the main rad's cooler have been cut. A lot happens in 21 years....

 

[Supercharged111]

Fan is going back on - not a problem as the mounts are on the body. It will just be the thickness of the AC rad away from the main rad - but airflow to the main rad will be improved.

The oil cooler for the trans is the problem now as it was mounted on the (now removed) AC rad.
Why it has a separate rad for the trans I have no idea. The pipes which once connected the trans to the main rad's cooler have been cut. A lot happens in 21 years....

From the factory the trans cooler had a mount that bolted to the core support. Sounds like yours has been replaced and installed by someone not creative enough to use proper mounts. Trans cooler will keep the trans alive much longer than if you didn't have one.

 

[someotherguy]

Oof... I'd keep the A/C and fix it. Even in cold climates, A/C is beneficial because it dries the air during defrost mode, makes it far more effective.

Richard

 

[Pinger]

Oof... I'd keep the A/C and fix it. Even in cold climates, A/C is beneficial because it dries the air during defrost mode, makes it far more effective.

Richard

I hear what you're saying but I'm just not for tracing leaks. I want a simple dependable truck. I'll focus on sorting the heating out. The immediate benefit is decluttering the engine bay. Easier access makes for better maintenance. I already have a heap of LPG (propane) stuff in there.

 

[Pinger]

From the factory the trans cooler had a mount that bolted to the core support. Sounds like yours has been replaced and installed by someone not creative enough to use proper mounts. Trans cooler will keep the trans alive much longer than if you didn't have one.

I don't know what has happened. The driver side of the main rad has the engine oil cooler. The passenger side once had the same for the trans. But the pipes have been cut and connected to the rad on the driver side in the pic below. It was mounted to the AC rad with plastic ratchet sort of things that pass right through between the tubes. Now the AC rad is removed, it's lost its mounting place. I'll sort something out easily enough but still a mystery why it is there at all - given the trans was once plumbed into the main rad - which would have helped warm the trans oil from cold. I won't be dispensing with the trans cooler though - no way.

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