Comforton AC Parts/Sensors? ('72 Full-Size)
February 25th, 2011, 08:00 PM
#1
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Join Date: Aug 2010
Location: MidWest
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Comforton AC Parts/Sensors? ('72 Full-Size)
Howdy,
Having troubles w/ the Comforton Automatic AC/HVAC controls in my '72 Ninety-Eight!
Had an Old School Mechanic Shop guy I trust completely FLUSH out the coolant system; he replaced the Heater Control Valve and the system is all sealed but no matter what I do w/ the control wheel inside the car I just CANNOT get ANY warm air at all inside the car, not on any setting -- even VENT won't get me any warm air! HELP! (Besides waiting until July-Aug anybody got any idea how to get WARM AIR flowing again?? 
) The Mechanic says the "switches & sensors in those older automatic HVAC Systems fry out and they're impossible to fix and it's hard to find replacement parts -- check with your Oldsmobile Club..." So, here I am! THANKS for the help!
Having troubles w/ the Comforton Automatic AC/HVAC controls in my '72 Ninety-Eight!
Had an Old School Mechanic Shop guy I trust completely FLUSH out the coolant system; he replaced the Heater Control Valve and the system is all sealed but no matter what I do w/ the control wheel inside the car I just CANNOT get ANY warm air at all inside the car, not on any setting -- even VENT won't get me any warm air! HELP! (Besides waiting until July-Aug anybody got any idea how to get WARM AIR flowing again?? ) The Mechanic says the "switches & sensors in those older automatic HVAC Systems fry out and they're impossible to fix and it's hard to find replacement parts -- check with your Oldsmobile Club..." So, here I am! THANKS for the help!
February 25th, 2011, 08:32 PM
#2
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Join Date: Feb 2011
Posts: 2
I think you have a door inside the box that is not opening to allow the warm air from the heater core, it may be a broken cable. If I remember correctly the comfortron system is essentially the same as the Cadillac system. I would get a 72 Cadillac shop manual, they were awesome in terms of trouble shooting. Most of the part you can still get from the antique auto air suppliers.
Once you get the Cadillac manual it should be fairly logical, most of the functions are mechanical rather than the later day electronic components.
Once you get the Cadillac manual it should be fairly logical, most of the functions are mechanical rather than the later day electronic components.
February 26th, 2011, 01:59 AM
#3
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Join Date: Jul 2006
Location: Northeast Ohio
Posts: 4,430
The 1972 Oldsmobile Chassis Service Manual should have a Comfortron section, shows everything and has diagnostics.
My '71 version has 27 pages dedicated to the system.
I sure wouldn't attempt to fix it without a manual, it looks like it would be a nightmare if you didn't know what you were looking at was supposed to look like or do.
You're sure the heater valve is working?
Got Vacuum?
Coolant in the radiator?
The light doesn't come on for no water, the sensor can't tell the engine is red hot unless it's in coolant.
I hate when that happens and warps my aluminum Chebby V6 heads.
First the heater doesn't work and a little bit later the engine does a death dance.
My '71 version has 27 pages dedicated to the system.
I sure wouldn't attempt to fix it without a manual, it looks like it would be a nightmare if you didn't know what you were looking at was supposed to look like or do.
You're sure the heater valve is working?
Got Vacuum?
Coolant in the radiator?
The light doesn't come on for no water, the sensor can't tell the engine is red hot unless it's in coolant.
I hate when that happens and warps my aluminum Chebby V6 heads.
First the heater doesn't work and a little bit later the engine does a death dance.
February 26th, 2011, 05:39 AM
#4
Connoisseur d'Junque
Join Date: Sep 2010
Location: The Hudson Valley
Posts: 21,183
If you read the Comfortron section of the manual thoroughly, and follow its troubleshooting steps, you should be able to find the problem. The only sticking is whether there are any "special" diagnostic tools - I'm not sure and don't have it in front of me.
Yeah. BMW has a similar feature. Theirs includes a carefully disguised bleeder screw that's AIRBRUSHED OUT of the owner's manual, and a radiator that's cheap to replace, but starts leaking at 60,000 miles (well, I think I'm supposed to say 100,000km in order to placate the Teutonic gods).
Thank Heaven for friends with machine shops
.
- Eric
Coolant in the radiator?
The light doesn't come on for no water, the sensor can't tell the engine is red hot unless it's in coolant.
I hate when that happens and warps my aluminum Chebby V6 heads.
First the heater doesn't work and a little bit later the engine does a death dance.
The light doesn't come on for no water, the sensor can't tell the engine is red hot unless it's in coolant.
I hate when that happens and warps my aluminum Chebby V6 heads.
First the heater doesn't work and a little bit later the engine does a death dance.
Thank Heaven for friends with machine shops
.- Eric
February 26th, 2011, 07:38 AM
#5
Oldsdruid
Join Date: Dec 2007
Location: Southside Vajenya
Posts: 10,295
You're sure you have the correct water valve- the one with the threaded recess for the coolant temperature switch? though if it doesn't see 120 degrees coolant temp the system should not work at all.
You also need access to an accurate parts book as Comfortron part numbers changed from year to year in their effort to get it reliable. The good thing is that Olds ATC parts are fairly plentiful- see them on ebay all the time.
Having a Comfortron tester makes it a lot easier too, if you can find one.
It's telling that Olds finally ditched it for Tempmatic in 1974 after fighting it for 8 years. A good friend who retired as an Olds Zone Service Manager told me that a large part of their Zone level service work from 1966-73 involved trying to make Comfortrons work, and they used a lot of "imagination" to do it.
You also need access to an accurate parts book as Comfortron part numbers changed from year to year in their effort to get it reliable. The good thing is that Olds ATC parts are fairly plentiful- see them on ebay all the time.
Having a Comfortron tester makes it a lot easier too, if you can find one.
It's telling that Olds finally ditched it for Tempmatic in 1974 after fighting it for 8 years. A good friend who retired as an Olds Zone Service Manager told me that a large part of their Zone level service work from 1966-73 involved trying to make Comfortrons work, and they used a lot of "imagination" to do it.
February 28th, 2011, 12:11 PM
#6
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Join Date: Aug 2010
Location: MidWest
Posts: 419
THANKS ALL!! excellent responses all!! (Thanks for telling me to be sure to check even "The Obvious" like water & coolant being IN the Radiator..." LOL! Funny, but TRUE also as in "Check first things FIRST!" 
) It does have plenty in it and no more leaks as best I can tell, I DID buy a proper '72 OLDS Service Manual and I'll print these page worth of good responses and tips and check it out once it warms up a bit more around here!! I"ll keep an eye to Ebay to be sure too! THANKS again and I'll follow up IF I get it fixed in the next month or two OR If I have more problems and not "enough imagination" to FIX them!
THANKS AGAIN GUYS!! WHAT A GREAT FORUM!! (Col. Wickham would be PROUD!!)
) It does have plenty in it and no more leaks as best I can tell, I DID buy a proper '72 OLDS Service Manual and I'll print these page worth of good responses and tips and check it out once it warms up a bit more around here!! I"ll keep an eye to Ebay to be sure too! THANKS again and I'll follow up IF I get it fixed in the next month or two OR If I have more problems and not "enough imagination" to FIX them! THANKS AGAIN GUYS!! WHAT A GREAT FORUM!! (Col. Wickham would be PROUD!!
)
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