Automotive Air Conditioning Information Forum (Archives)

RailRoader78 on Sat August 29, 2015 9:10 PM

Year: 1994
Make: Honda
Model: Civic
Engine Size: 1.6
Refrigerant Type: R134a
Country of Origin: United States

I have a 1994 Honda civic ex 1.6l the entire system is new and flushed. My question is no matter what the ambient temperature is the vent temp won't go below 49. As soon as it hits 49 it will go up a few degrees then go back down. Could it be the ac thermostat I have not tested it yet. Pressures were ok. At 1500rpm low side was about 35 or so and high was up to 300 it is also 110 degrees ambient my vent temp at that idle speed was high 50's low 60's. The 49 degree thing is while driving on the freeway.

Cussboy on Sun August 30, 2015 10:15 AM

I'm in Phoenix, also 110F, and 49F vent temperatures don't seem bad, that's a lot of temperature drop !!! Remember your interior is also 110 - 150F and seats, dashboard, etc. are all that temperature, and that air goes into the evaporator to be cooled..

mk378 on Sun August 30, 2015 10:33 AM

Check that the water valve is closing fully to turn off the heater core.

The thermostat is electronic, mounted on top of the evaporator box. I think that replacement requires removing the refrigerant and pulling the box to get the thermistor out of the evaporator core. You could try resistors in parallel with the thermistor to change the setpoint.