Part of the process was to check that the two duct temperature sensors and two interior cabin sensors are working. Maybe somebody else already discovered this method, but I hadn't come across a write-up anywhere, so it was new to me: I found a way to do the resistance test on all four sensors relatively easily (no removal of sensors or disassembly of lower part of dash is required for this test -- though like me you may already have removed the panels and glovebox, etc, to check everything else out). All you have to do is to pull out the ECC control module from the dash, disconnect the three green connectors on the back. (Removing the radio first makes it easy to push on the back of the ECC module to release it from the panel).
- Remove the three green connectors on the back of the ECC module.
- ECC_Connectors.jpg (91.61 KiB) Viewed 15303 times
- Brown, Yellow and Green wires going into back of large connector.
- Measuring the resistance of one of the Cabin interior temperature sensors (the Brown-Green pair)
Below I'm measuring the opposite side of the car (the Brown-Yellow pair) and getting 7.56kOhms.
- Measuring the resistance of the Brown-Yellow (GND - #1) sensor
- Duct temp sensor test
Just thought I'd write this up as a quick and handy test to allow measuring all four of the interior temperature sensors in a relatively quick and painless way. All four of my temp sensors appear to be reading roughly similar values. I also checked that the fans located behind the cabin temp sensors appear to be spinning normally.
The fifth sensor in the AC system is at the bottom front of the car mounted to a metal tab right in front of the radiator (on my '97 -- I think '95 and earlier have a different type of sensor that is located near the windshield on the passenger side). When I tested that sensor I got about 500 Ohms, which matched the reading of the second temperature sensor located just above it in front of the radiator.
