Automotive AC

[donald w. miller]

Greetings to all from Don and Margaret Miller

We are now in the midst of refurbishing a 1975 Glenbrook and appreciate very
much the abundance of information we have gleaned from this site and from
the forum members.

We find it necessary on hot days to cruise with genset and overhead AC units
running, as our automotive AC output is inadequate.

Is this true for all GMC motorhomes or an indication our automotive AC needs
a tune-up? It appears to be working as it blows cold air but not "enough"
cold air.

I would be interested in hearing if anyone has added a rear evaporator /
blower or taken other steps to enhance the output.

It seems the 12.5 cu in compressor should have plenty of capacity.

The condenser looks quite large too, but maybe an even larger one is needed?

Any AC ideas are of great interest tonight for it is hot and humid in
Virginia.

There must be a better way than cruising on hot days with genset and
overhead units running.

Thanks

Don

 

[jim bounds1]

Don,
You are right, your dash air does not work well and no, not all GMC
coacches have this problem. The 77 & 78's have an updated duct assy.
that throws the air out well.

Do you have a vent assy. under the center of your dash? If not, you
need the GM update kit. Basically GM found they made a bobo, the heat/
AC box under the dash did not have enough outlet vents to relieve the
air pressure inside the box. It is probobly snowing inside the box but
you only feel a small bit of the air. The update kit cuts a hole in the
air box, redesigns a vent door and dircts the box air to an add on vent
assy. under the center of the dash.

If you need one of these kits, I believe Golby 1-800-872-1462 has the
kit. Installation is another story. A pretty involved set up, it
should not be attempted by someone unfamiliar with AC system and then
allow a full day for the mod. For more questions call Golby or Alex
Serun.

Yes, I have added a rear AC unit along with the dash system and the set
up worked pretty well. The compressor is plenty large to handle the
additional load. I located the unit under the refer and installed vents
next to the entry door, under the refer and in the bathroom. The bath
ended up being the coldest room in the coach. If you have interest in
this, give me a call.

Hope this helps.

Jim Bounds www.gmccoop.com

>
> Greetings to all from Don and Margaret Miller
>
> We are now in the midst of refurbishing a 1975 Glenbrook and appreciate very
> much the abundance of information we have gleaned from this site and from
> the forum members.
>
> We find it necessary on hot days to cruise with genset and overhead AC units
> running, as our automotive AC output is inadequate.
>
> Is this true for all GMC motorhomes or an indication our automotive AC needs
> a tune-up? It appears to be working as it blows cold air but not "enough"
> cold air.
>
> I would be interested in hearing if anyone has added a rear evaporator /
> blower or taken other steps to enhance the output.
>
> It seems the 12.5 cu in compressor should have plenty of capacity.
>
> The condenser looks quite large too, but maybe an even larger one is needed?
>
> Any AC ideas are of great interest tonight for it is hot and humid in
> Virginia.
>
> There must be a better way than cruising on hot days with genset and
> overhead units running.
>
> Thanks
>
> Don