AC not working: Climate Control Module?

[SleepyHead98]

Hey guys, got a question.

The jist, new pump, new evap, new dryer orings what not. ETC ETC. worked fine for weeks, its still holding perfect pressure, so i do not believe this to be mechanical at all.

Now, Problem is, ac will not come on. I believe it to be climate control module, Heres why. Pressure is good. Relay is good, swapped AC relay out with horn rely. Volts are coming to pressure sensor: I put a paper clip in the wiring at the appropriate wires to bypass the sensor. Still did not come on. Left paper clip in Pressure sensor wiring harness, and went inside vehicle to press AC on, (the little button that turns clutch on) Does not come on. The outside air vs inside air circulation switch does not work either. It is stuck on outside air. I can switch the heat on, but thats it. The actuator door works great, so no problem there. Basically, it seems the signal to turn the compressor on is not happening. What do YOU think it is?

(Problem started after I was having trouble getting temp at right setting. Turns out I put too much Oil in compressor (2.5 over)) drained out appropriate amount of oil, and refilled with appropriate amount of freon. Car finally blew at 42 Deg at all blower settings *Near 100 degress outside*. So, Did a final test on the HWY when I was coming home from work, Turn AC all the way up to HIGH and FULL COLD, blew perfectly. Ran it for 1 minute like that, then turned fan back down to 1 FULL COLD. And it all just quit. No AC, only heat, no air circulation options. )

[Tech II]

You were getting 42F out of registers with the temp outside 100F?

That sounds too good......wonder if the evap was freezing up.....

You don't say what year the vehicle is....if you have a 3 wire pressure sensor in the system, it can't be jumped.......by jumping it, you make the PCM think the pressure is too high or too low....if the sensor is reading correctly, then you need to know if the PCM is getting a "request" from the A/C control head.....

[brcidd]

Never ever jumper a 3-wire transducer- you could smoke the ECM!

test for ECM ground signal at a/c relay coil - if not there- you have input issues- I suspect the transducer- since you tied to jump it..

[SleepyHead98]

Ha, cool. Thanks for the info on the three wire jump. ECM is fine, guess I got lucky. So, I got a used head unit, craigslist 20bux. Thew it in on the spot and it works just fine.

How would I test a three wire pressure sensor by the way?

98 olds cutlass (Chev Malibu) 6 cyl. v5 compressor.

[brcidd]

tap into it- 1 wire is 5volt, one is ground, the other is reference return of the transducer- should show 1 volt per hundred psi-- so 70 pounds is like 0.7 volts

[la1]

tap into it

uh oh ...and just how to "tap in" never stick a pin or break the insulation, never back probe a weather pack connector and never stick a probe into the connector, it will deform the connector , buy the correct adapters.