AC question

[sunvalleyray]

While driving up mountain pass on very hot day (104) my AC vents appeared to be blowing air that was less cool than normal. After car sat AC was blowing cold again. My question is: does SVX have override switch that shuts off AC compressor when engine/radiator coolant gets to a certain temperature? If not, what is explanation?

Thanks,

sunvalleyray

[ensteele]

Did you have your windows or sunroof open?

[redlightningsvx]

Mine strangly did this today also. I had my heater on this moring and after I left work I turn my a/c on and it was a little cool for 30 min straight. Then I let it sit for about ten min on high and it started blowing out ice cold and has since.

[NiftySVX]

Check your codes and make sure you don't have a evap temp sensor code or a mode door code.

[redlightningsvx]

Mine showed up a code 14 on the select monitor, but I haven't looked in my FSM to find out where it is.

[NiftySVX]

Originally Posted by redlightningsvx

Mine showed up a code 14 on the select monitor, but I haven't looked in my FSM to find out where it is.

I believe that is the evaporator temp sensor, depending on the model year it is either in the fins of the evap core or suspended very near it. It requires removal of the cooler box. If that is code 14, it will cause the exact symptoms you describe and will eventually cause the thing to not blow cold at all.

[subiemech85]

endwrench http://endwrench.com/images/pdfs/SVXInfo.pdf

[redlightningsvx]

Originally Posted by NiftySVX

I believe that is the evaporator temp sensor, depending on the model year it is either in the fins of the evap core or suspended very near it. It requires removal of the cooler box. If that is code 14, it will cause the exact symptoms you describe and will eventually cause the thing to not blow cold at all.

That sucks, I looked at the price today and it's about $120 for the sensor. The select monitor showed Code 14 evaporator sensor then it displayed it as OPEN. So would that mean the sensors junk? I also just looked at the FSM and it doesn't look that bad to change. just remove the glovebox, recover refrigerant. The sensor loos like it sits infront of the evaporator fins.

[trophy956]

hi i you asked if the a/c cuts out when the engine temp gets to high ,yes it does ,the ECM has the final call on a/c operation

[alia176]

Originally Posted by redlightningsvx

Mine showed up a code 14 on the select monitor, but I haven't looked in my FSM to find out where it is.

You have a select monitor? How cool is that!!! I'd like to get a hold of one of those or at least use one to figure my cruise control, but I digress.

Yes, the evap sensor is easy to access once you remove the cooling unit that's behind the glovebox which has somewhere near 1,000 screws holding it together I believe the sensor is located inside the shiny alum foil tape. See pic.

[NiftySVX]

The one shown in that picture is the refrigerant temp sensor. The evaporator sensor is different, and if I recall correctly the 134a models had the sensor in the fins and the older ones had the resistor and it was placed in front of the evaporator. Funny, I was not aware of this end wrench article until just now, as when I replaced the sensor in one of my vehicles I put it back in the holder that suspended it in front of the evap and left the resistor installed. Whoops.

And P.S I always replace both. I never wanted to take that box out again.

[redlightningsvx]

I looked the evap sensor up at work and it show it sits in front of the fins on the top and the refrigerant sensor is on the otherside on the bottom for a 1994. The evap sensor alone was $120 so i'm going to do this as my winter project.