Heater settings for air con

quote:

Originally posted by 74LQQKR:
I know that this is a pretty stupid question but I have to ask. Every thing is running cool now and I'm starting on the air con. The question is what are the 3 settings on the heater i.e temp/def/ etc. when you turn the knob for the air? I assume that you set to cool then what. I'm sure I need some freon but I want to make sure that I have things set right befor starting on the air con.

thanks

Aaare you running a stock condenser unit? If you are chances are the freon will leak out almost as fast as you can put it in. Aand with freon being what it is, $$$ and and environmental hazard, I think you may want to check your condensor for leaks. I had heard that the exaust tended to react with the aluminum fins causing small leaks.

the best advice for the heater / ac question is to install heater shut-off valves so that no hot water comes into the interior of the car. This helps reduce heat 2 ways. There is some heat transfer in the tubes running through the console and the air blows through the heater core and then through the evaporator so that unless you can completely shut off the heater valve there is some hot water circulating through the system. the cable on the dash does not allow the heater shutoff valve to close completely. Installing heater shutoff valves in the engine compartment keeps all of the heat on the outside of the passenger compartment

Thanks,
Every thing is stock so your right I most likely have many leaks. What should the 3 heater switches be set to on the dash when I turn on the air condition knob? I assume that the heater shut off valves go 1 on each heater line in the engine compartment? I guess with my new Fluidyne and 2 sucker fans the temp should stay ok without any flow to the heater core.

You have three sliding levers. Top is 'floor---def', middle is 'car---def', bottom is 'off---hot' The 2-speed fan can force air out to three locations - under dash, dash vents, defroster vents. With the top lever in 'floor' forced air WILL exit from the side of the heater/AC box (under the dash) AND will exit through the dash and/or defroster vents. With the top lever in 'def', forced air can only exit from the dash and defroster vents. Now the middle lever determines how the forced air is divided between the dash and defroster and it allows you to send air to just dash (car), just defroster (def), or a mix of the two. For AC, you may find the under dash vent to be a worthless distribution of cool air (unless you like cool legs more than a cool body), so take the top lever and move it to 'def'. Now you can decide how to divide that cool air--- send it all to the dash vents, all to the defroster vents, or split it between the two with the middle lever slid somewhere in the middle range. Bottom lever is a variable flow control for your hot water flow to the heater coil, and the rotary AC knob is a temp control for the AC thermocouple. Clear as mud now? And yes the shut off valves (usually just 1/4 turn ball valves from the hardware store with appropriate nipple adapters and hose clamps) get mounted in the engine bay. Pick a spot up high to reach from above, or down low where you can reach under the car and get to them (my choice).

R12 Freon will do a better job cooling that 134 and is still available - though not all garages have kept their R12 machines. You can have a good shop use a dye and check for leaks. You can also go online and take the test to become a licensed AC tech (cost about $20) and then (legally) buy R12 off eBay for about $20 a pound. Have fun.

Larry

Thanks Larry,

That was a great explanation, just what I was looking for. I believe you are the Larry I sold my old Mallary parts to. Hope all is well with you.

curt

Keeping in mind that you should occasionally open the shut-off valves to allow coolant held in your heating system to recycle preventing it from deteriorating.

My factory heater valve works perfect. I have however replaced my stock condenser with a high effecient cross flow from Arizona a/c

quote:

My factory heater valve works perfect.

This is open to debate. Standard Pantera think is the stock valve and cable control were not designed together. Thus, the throw of the lever does not give complete throw of the valve. You can adjust the valve functioning parameters (at the cable clamp on the heater valve) two ways --- so the dash lever closes it completely but won't fully open it, or the other way around. Fully closed option will limit heat in winter, as it won't fully open the valve. Fully open option (to maximize winter heat) means it doesn't fully close, and in summer your AC is having to deal with air being heated as it travels through the heater coil that is being fed by the trickle of fluid getting past the almost-but-not-quite closed heater valve. Shut off valves in the engine compartment can serve as a complete shut off, allowing you to adjust the cable clamp at the heater valve for full open in the winter, when you will of course open the engine compartment valves.

Larry