93 supreme sl weirder A?C problem

[curts11]

I only added this as a new thread in case comments in other thread dont get read...
93 supreme sl 3.1 4sp auto w/digital automatic comfort control

I am also having a weid issue w. ac also...my problem; if you watch the outdoor temp, you will note dramatic changes therefore, it cools on high one min and then suddenly the heat is on? does anyone know where these RTDS are located, is it a bad ecu or...........

my post w/out the quote...in other weird ac issue 93 olds

I am also having a weid issue...think about this... when you ac is blowing at 45 mph, is your climate control in the recirculate position? if so air flow of the exterior will not increase with speed , that would only happen if in fresh air position.. the ac and heat are controlled by rtds sensing indoor and outdoor conditions and the calling for heat / ac the variation of setpoint will cause fan speed changes. these rtds (thermocouples) are wired into the ecu, and I believe the ecu makes the final adjust to fan speed and or cool/heat all based on your desired temp setpoint????? any care to ad lib please do my problem if you watch the outdoor temp you will note dramatic changes therefore, it cools on high one min and then suddenly the heat is on? does anyone know where these RTDS are located, is it a bad ecu or...........

[3100MPFI]

the ECU does not control anything with the AC system other than the COMPRESSOR CONTROLS. The AC head unit (ATC control interface) controls everything to do with FAN SPEED, TEMP SETTINGS, RECIRCULATE, and VENT SETTINGS.

The INSIDE AIR TEMP SENSOR. Check it to be sure it is working properly and has not become clogged, or disconnected.

You know the little GRILL between the 2 passenger air vent? That is the INSIDE air temp sensor. Well, the sensor is mounted behind that grill. Rip off a small piece of paper just slightly bigger than the opening in the grill, and turn your ac on and the fan speed to HIGH (MAX). With the fan running on high, put the piece of paper over the grill, and see if it stick there. If it does stick there, turn off the AC and see if it now falls off. If it DOES, then that means that the interior air temp sensor is getting proper airflow, so that is one thing ruled out.

The OUTSIDE air temp sensor is located in front of the car between the bumper, and the radiator/condensor. It is bolted to the brace that goes in front of the condensor and up to the hood release latch. There is no real way to test it other than know what the outside temp is and see if your display shows it.

The OUTSIDE temp works best when the car is in motion.

Next thing, is check to see if you have any ERROR CODES in the AC system. When you start the car, does the *F, or *C light on the display FLASH? It will flash for up to a minute if there is any error codes. If it DOES, then press the OUTSIDE TEMP and BI-LEV at the same time (with the key on, or car running), and the display will cycle through any error codes. If it just displays 00, then there are none, and you can press OFF to get out of there.

With the problems you are discribing, it sounds to me like the control unit itself is going bad. When mine went out, I had not temp controls, or fan speed controls. Sometimes, when I turned it OFF, the fan would keep blowing.