Just got the a/c working again (134 conversion) and used it last night for the first time for more than 5 minutes - ran 40 min with a/c on max and fan speed on low with 85degree temp outside with 100% humidity for about 30 miles and when I came back to the car the passenger rubber floor mat had a pool of cool water on it. I looked under the car and there was a puddle of water from the a/c box tube draining nicely as it should because I thought that was plugged up and would cause that problem but nope. I rubbed my hand all over the a/c fiberglass box inside the car and it was COVERED in condensation - so much so that it was dripping on the floor from ALL over it. Any ideas on what to do?
1970 air conditioner inside box condensation on outside of box dripping on floor
- Thread starter bsedwebt70-5.0
- Start date
You probably experinced a worst-case scenario with the A/C on high, the fan on low, and in 100% humidity @ 85*. Something you can try is using adhesive-backed black foam to insulate the box from ambient air. Also make sure your evaporator temp sensor is working. Its purpose is to shut off the compressor before the evaporator can ice over. Also try turning off the A/C while keeping the fan on for a while before you stop so the evaporator can warm up some.
Thanks for the reply - I am thinking where to find some black foam that will not hold water if it does it again - Also - how to I check the evap temp sensor without tearing into the heater core box? If it is malfunctioning - any ideas on ways to avoid that - just got it back together and do not want to mess it up
According to my '68 factory manual, the icing switch is wired in series with the blower switch and clutch so it can cut the compressor when the evap gets too cold. I dont know how to test it short of running the car with the A/C on and the hood open. The compressor should run for a while, the shut off, then come on a little later, then off again repeatedly. If it never shuts off and you have a full charge of Freon, then the switch is likely malfuctioning. As for the foam, you need some kind of adhesive-backed closed cell foam. Urethane works well in a wide ariety of environments. It was also just an idea carried over from refrigeration; I've never tried it myself. McMaster-Carr has lots of the stuff(and just about any industrial item you could want).
closed cell foam - is that like pipe insulation or roll bar padding? Hmmmm - where to find it locally - Lowes? Home Depot? Ace? ... I have yet to pop the hood and watch the a/c yet but I will do that in a few days when drive it again and the air gets nice and cold after running down the road a while - that way I am sure it got cold enough - if it does not shut off occasionally I guess that means tearing into the dash again.... Is it supposed to cycle off like that on MAX? I could just run it on regular -hmmmm...
Yeah, pipe insulation is closed cell, but I'm afraid I dont know where to get it in sheets other than ordering it. If the foam is kind of shiny on the outside and you cant squeeze the air out of it, its very likely closed cell. As far as I know, the icing switch should work no matter what setting you have it on. If its really, really hot out then obviously the evaporator will take longer to ice over(if at all) and th switch will cycle less often.
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