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1st Gen. Ram - All TopicsDiscussion for all Dodge Rams prior to 1994. This includes engine, drivetrain and non-drivetrain discussions. Anything prior to 1994 should go in here.
Thanks for all the tips ya'll. The clutch fan is doing its job with bellowing fan and no rats nest in hvac box as I did the access hole years ago and keep it clean. The only thing that got me thinking I used to have cooler temps was the compressor used to cycle more, and now it stays on. On a whim I "burped" the low pressure side ( not running) and air came out. It seemed like the compressor started cycling (the next mornig when it was still cool) and the temp was lower, also the junction box where the sight glass is wasnt hot any more. Unfortunately this "normal" condition didnt last long as the merc crept up😠 does this temporary "burping air "mean anything?
Thanks for all the tips ya'll. The clutch fan is doing its job with bellowing fan and no rats nest in hvac box as I did the access hole years ago and keep it clean. The only thing that got me thinking I used to have cooler temps was the compressor used to cycle more, and now it stays on. On a whim I "burped" the low pressure side ( not running) and air came out. It seemed like the compressor started cycling (the next mornig when it was still cool) and the temp was lower, also the junction box where the sight glass is wasnt hot any more. Unfortunately this "normal" condition didnt last long as the merc crept up😠 does this temporary "burping air "mean anything?
It means you let off a little of the freon.
The entire system settles down to the same pressure when it's off, determined by the coldest part of the system. Of course there will be a little pressure on the low side.
your best bet would be to have someone who does refrigeration look at it.
The entire system settles down to the same pressure when it's off, determined by the coldest part of the system. Of course there will be a little pressure on the low side.
your best bet would be to have someone who does refrigeration look at it.
Of course I knew that😉 but was hopeful for a cause,effect,solution idea bubble😕 will do j_martin.
The factory dodge 91.5-93 has the electronic cycling clutch relay. The *factory* set point I believe is 48-55F. So, you should never get 40 degree vent air unless you lower the set point.
I believe many ppl simply pull the measuring point out of the tube a bit. On mine(for better or worse), I added a resistor. I didn't want to have issues with defroster on 33F rainy days. So I think I adjusted it down maybe 45F.
Make sure your heater control valve is closing fully. Else you are running heat+a/c. The other thing, maybe the fresh air vent diaphragm actuator could be bad and be pulling outside air @ max a/c.
I was thinking on doing the PS intercooler mod also- so I will be in the same boat with you soon. I may do the water pump upgrade + fan clutch at the same time. I think I would add some sort of pressure switch to the a/c to relay an electric fan clutch + have a engine temp driven relay. Then again, maybe just a fresh clutch + newer style fan.
Did longer trip the other day and system performed normally. The fan clutch was active most of the trip so I think my cleanout of the condenser fins was releasing enough heat to work the fan. Guess ill leave well enough alone. Thanks for tips all.
The measure of heat content in air is called enthalpy. As you can see in the chart, 32° C (90°F) at 100% RH has a heat content of 112. At 50% RH, it's 70. At 30% RH it's 58. Humidity makes a huge difference.
When we set up AC for large gatherings of people, it's sometimes better to throw away the air and replace it with chilled outside are, than to extract the heat and moisture(enthalpy) from the used air.
. Just so happened I taught this subject to the LU 104 4th year apprentices a couple weeks ago in their HVAC systems design class. Good find JM!
07-03-2015, 08:21 PM
