[bigear1]

We have a 1980 38' Chris Craft Corinthian with two A/C heat units. The problem is that even with the temp control turned all the way down and the fan on its lowest, it gets very warm inside. We are forever up and down turning it on and off to control the comfort level. Would anyone know if and how we can hook up a thermostat?

[Brooke's Buddy]

On some controls there is a setting on the reverse side of the panel,it sets what a A/C tech told me is a "set point". i don't want to send you in the wrong direction,too many types of control panels and yours may not have a setting. does it have three knobs? if the temp knob is a manual type on the reverse there is a hole for a small flat head screwdriver. The "marine air" control panel from the 90s had a penguin on it,one users manual for the small penguin and a completely different manual for the large one!

[SeaEric]

Are you living aboard? If so, it may perhaps be worth the $ to upgrade to the newer style digital controls. I know some folks who have done this job themselves as a DIY. Me- I would hire a trained tech.

Originally Posted by bigear1

We have a 1980 38' Chris Craft Corinthian with two A/C heat units. The problem is that even with the temp control turned all the way down and the fan on its lowest, it gets very warm inside. We are forever up and down turning it on and off to control the comfort level. Would anyone know if and how we can hook up a thermostat?

Hi Bigear1...Steve Here~

From what I can tell from your brief description...It sounds like you have "3 knob" manual controls...The Temp control IS a thermostat like you might find in a window unit at home.

If you are setting it all the way to the warmest setting (fully counterclockwise) yes it will get very warm in the cabin.

Try this...Leave it set to the warmest setting, and once the cabin feels warm enough to you...Slowly start turning it toward Cooler (clockwise) until you hear it "Click"...Then leave it there....It should then cycle the compressor to maintain that temp within about 3-4 degrees, and will also automatically switch to cooling if needed to maintain that given temp.

The fan will continue to run but the compressor will cycle on & off to maintain that cabin temp...

There are actually 2 "Clicks" close together, and that's why I say to turn the knob slowly...The space between clicks is cabin temp at the time it clicks (compressor off)...

If you turn it a bit too far (past the second click) the system will start to cool so you will then need to turn it counterclockwise a bit till it clicks again.

Once set, take note of the arrow's position on the dial and you can always come back to that temp setting...Rotating clockwise till it clicks will lower cabin temp a few degrees...Rotating counterclockwise will raise cabin temp a few degrees...Once you find your Happy spot it does not need to be changed again.

I explain it a bit further on my site, and thanks Skip for the referral.

Steve~