Chevy Express AC quits on long hills?

[sknight]

If you run one or the other I doubt you'll see much change in fuel economy.

Could always run the engine driven AC normally then fire up the genset and roof AC in hilly areas as needed. Might be the best compromise.

[Mich F]

Originally Posted by sknight

If you run one or the other I doubt you'll see much change in fuel economy.

Could always run the engine driven AC normally then fire up the genset and roof AC in hilly areas as needed. Might be the best compromise.

That's why I suggested he turn off the dash air and use the roof air in those "mountain conditions".
Years ago I had a Chevrolet powered motor home, and running that dash air or not, made a very noticeable difference in how the engine performed.
No idea on which is really cheaper to run, but lessening the load on the engine is enough reason for me to shut off the dash air.

[sknight]

When I worked at Chevrolet dealers they told us that it takes 20HP to spin the compressor. Knowing the system and how it works that makes sense.

But there sure is a difference when you turn that puppy off, isn't there?

[Mich F]

Originally Posted by sknight

When I worked at Chevrolet dealers they told us that it takes 20HP to spin the compressor. Knowing the system and how it works that makes sense.

But there sure is a difference when you turn that puppy off, isn't there?

There was a huge difference with my 5.7L Chevrolet powered motor home. I've never noticed much of a difference with a 5.4L Ford V8 in an F250, with slide in camper, even while pulling a 6,500# boat/trlr, or in either of two of my Ford V10 powered motor homes, with the 24'er pulling that same boat. It stands to reason there has to be a difference, but I haven't noticed any.

[power guy]

I know all these answers are viable but its my guess its the full throttle valve that is disconnecting the AC. the easy way to check this is go out on the highway and push it to the floor, i'll bet the AC drops out. If this is the case then Its supposed to do this.