Since a couple posts have appeared lately complaining about A/C systems not being able to handle heat, I did an instrumented test of my 80s today. One of the complaints has been that they work OK at freeway speeds, but in stop and go traffic several complain their system is healthy but cannot keep up with the heat and the air coming out the vents isn't as cold. I do not experience this on either of my 80s (though I'm not in 110 degree heat like some of you are - yowza!).
Here's what I measured on a 94 degree day. Both truck cooling systems are as close to new as possible, with the 97 even having a new OEM radiator a couple months ago as PM. The temps were measured at the driver's window vents since testing showed it to be a couple degrees cooler on both trucks. Both on recirc, full cold, fully warmed engine and a/c on for at least 15 minutes, fan position #2.
The 1993 blew 43.8 - 45.9 degree air at 70mph. At the end of the exit ramp (huge heat load), it blew 44.8 - 47.6 degrees. The range is simply when the compressor cycles on and off. In subsequent stop and go traffic, it blew 43.1 - 45.8 degrees. In full shade (my garage) it blew 42.8 - 45.7 degrees.
The 1997 blew 45.6 - 47.5 degree air at 70mph. At the end of the exit ramp (huge heat load), it blew 46.8 - 48.3 degrees. In subsequent stop and go traffic, it blew 45.0 - 48.2 degrees. In full shade (my garage) it blew 46.9 - 49.4 degrees.
When I stop at a traffic light, I personally cannot discern a difference in vent temperature and now that I've measured these, I'm not surprised. Both trucks blow ice cubes when needed, but clearly the older system seems a bit colder. They're both fully charged and I've cleaned both of the A/C condensors with my soaking technique to clear them of accumulated road grime and debris.
The tool I used is a pricey MAC Tools digital thermometer designed with a probe for this purpose. I borrowed it from a mechanic at a nearby dealership.
If you experience a loss of cooling at stop lights in this ambient temp range, consider taking a good look at your cooling system and your a/c system. You just might find things are not as healthy as you think, and a bit of PM could net you ice cold air.
DougM
Here's what I measured on a 94 degree day. Both truck cooling systems are as close to new as possible, with the 97 even having a new OEM radiator a couple months ago as PM. The temps were measured at the driver's window vents since testing showed it to be a couple degrees cooler on both trucks. Both on recirc, full cold, fully warmed engine and a/c on for at least 15 minutes, fan position #2.
The 1993 blew 43.8 - 45.9 degree air at 70mph. At the end of the exit ramp (huge heat load), it blew 44.8 - 47.6 degrees. The range is simply when the compressor cycles on and off. In subsequent stop and go traffic, it blew 43.1 - 45.8 degrees. In full shade (my garage) it blew 42.8 - 45.7 degrees.
The 1997 blew 45.6 - 47.5 degree air at 70mph. At the end of the exit ramp (huge heat load), it blew 46.8 - 48.3 degrees. In subsequent stop and go traffic, it blew 45.0 - 48.2 degrees. In full shade (my garage) it blew 46.9 - 49.4 degrees.
When I stop at a traffic light, I personally cannot discern a difference in vent temperature and now that I've measured these, I'm not surprised. Both trucks blow ice cubes when needed, but clearly the older system seems a bit colder. They're both fully charged and I've cleaned both of the A/C condensors with my soaking technique to clear them of accumulated road grime and debris.
The tool I used is a pricey MAC Tools digital thermometer designed with a probe for this purpose. I borrowed it from a mechanic at a nearby dealership.
If you experience a loss of cooling at stop lights in this ambient temp range, consider taking a good look at your cooling system and your a/c system. You just might find things are not as healthy as you think, and a bit of PM could net you ice cold air.
DougM