Gus Manrique Posted June 29, 2016 Share Posted June 29, 2016 AC turn On but noting happen, I replaced all component Compressor, expansion valve, dryer, temperature sensor. When I turn ON I have tio provide ground to relay manually then compressor starts working, temp sensor works fine, if reach temp sensor command temp and turn Off the compressor, then never coma On again until manually grounding. If compressor is working and I stop and turn ignition Off then after some minutes turn ignition ON AC works fine, only If senor temp commands to turno Of AC or If I turn Off the knob the compressor will never come ON again. I will appreciate your help. Gus. 0 Quote Link to comment Share on other sites More sharing options...
Charmedsycophant Posted July 6, 2016 Share Posted July 6, 2016 what do you mean provide ground to relay manually like your standing in front of car touch wires off of places im having a issue where my fluid is good fans work great but the compressor isnt responding to the knob I had a few ideas im gonna try if they work ill post what I did 0 Quote Link to comment Share on other sites More sharing options...
mad1macs Posted August 12, 2016 Share Posted August 12, 2016 Same thing here. I had a probe and it was wired with an aux switch that turned the compressor on. Everything else worked like it was supposed to, just had to remember to turn the switch on...I did not hook it up so I don't know how it was done...help 0 Quote Link to comment Share on other sites More sharing options...
thefoeyouknow Posted August 13, 2016 Share Posted August 13, 2016 Get a shop to check your evaporator temp sensor. It's likely reading -40F to the PCM. The PCM decides that's too cold for A/C, and denies the A/C request. 0 Quote Link to comment Share on other sites More sharing options...
komondor Posted August 13, 2016 Share Posted August 13, 2016 yes if you look there are 2 simple fixes one involves putting in a resistor to fool the AC temp sensor the other solution is to put in a new temp sensor in an easier location which makes sense if you live in a cold climate. I spent about 700 bucks to a shop to get it fixed because I did not search enough online or in the forums. 0 Quote Link to comment Share on other sites More sharing options...
thefoeyouknow Posted August 13, 2016 Share Posted August 13, 2016 Don't take shortcuts. I've seen some of those come in with grotesquely damaged AC systems. The compressor never shuts off when you do it that way. You'll get freezing, swelling, and that's just the easy ones. The sensor is cheap and it's time consuming to install, but not difficult. 0 Quote Link to comment Share on other sites More sharing options...
mad1macs Posted August 16, 2016 Share Posted August 16, 2016 Well I jumped in a new A/C temp sensor, have a parts car, cut the connector out of the parts car for this jumper, removed the 3&4 wire from the blue connector and attached it to the wires, reinstalled the connector. No workie..now what? Had a shop look at it and they said the pcm was not sending a ground signal to the relay telling it to close, thereby engaging the compressor..but they could not fix it or reprogram the computer. 0 Quote Link to comment Share on other sites More sharing options...
thefoeyouknow Posted August 16, 2016 Share Posted August 16, 2016 You still need to actually test the sensor. What's happening is the pcm is receiving a clutch request, and for some reason denying it. You need to find out why. The sensor is common, but not exclusive. 0 Quote Link to comment Share on other sites More sharing options...
mad1macs Posted August 16, 2016 Share Posted August 16, 2016 How would one go about testing the sensor? 0 Quote Link to comment Share on other sites More sharing options...
thefoeyouknow Posted August 16, 2016 Share Posted August 16, 2016 With a scantool, of course. When these sensors fail, they tend to fail open so that the reading to the pcm is interpreted as -40f, which to the pcm is too cold to grant the clutch request. Sort of like "it's minus 40 and you're asking for AC?!, gtfo, No." there are other sensors involved such as the AC pressure sensor which reads high side pressure to the pcm. If this is sending a reading too high or too low, pcm will deny request. Scantool. 1 Quote Link to comment Share on other sites More sharing options...
eGuru Posted August 16, 2016 Share Posted August 16, 2016 Yes get a scantool. Since you changed the sensor, problem may be the HVAC temperature controller. 0 Quote Link to comment Share on other sites More sharing options...
mad1macs Posted August 19, 2016 Share Posted August 19, 2016 HA HA, That's what I already know...Scan tool that can read the sensor? or just tell me it-40 here under my dash in 100 degree heat. I have already changed the other sensors under the hood. Can't seem to find anyone who can tell me if the one I have in my hand is good or not. If you remove the 2 wires from the connector, the ones that go to the installed sensor and no where else wire in another one that is good on the side going to the ECU it should read what it is supposed to even though it is not in the dash, or are you going to tell me it has to have air flo to it to register anything? 0 Quote Link to comment Share on other sites More sharing options...
eGuru Posted August 20, 2016 Share Posted August 20, 2016 The goodness of the sensor is irrelevant if the HVAC controller which converts the analog resistance values to digital and sends that info to the ECU is in fact defective. So you need to find out what the ECU is being told. 0 Quote Link to comment Share on other sites More sharing options...
mad1macs Posted August 20, 2016 Share Posted August 20, 2016 well gee the computer says -40 degrees. 0 Quote Link to comment Share on other sites More sharing options...
eGuru Posted August 20, 2016 Share Posted August 20, 2016 (edited) Does your replacement sensor measure about 37K ohms (when disconnected from the vehicle)? Are you seeing any voltage at one of the terminals (can't say which colour wire)? Does the non-powered wire show a low resistance to ground? Edited August 20, 2016 by eGuru 0 Quote Link to comment Share on other sites More sharing options...
mad1macs Posted August 20, 2016 Share Posted August 20, 2016 (edited) Well I fixed the A/C this morning. Went and got a new sensor from NAPA $23.81 removed the blue connector from behind the glove box, removed the Yellow/purple stripe and the purple wire from the connector, wired in the new sensor, replaced the plug, turned the car on and the a/c came on and functions like it should, everything works. took about 15 minutes. TIP: while at NAPA get a couple of female and male connector pins and add a short piece of wire between them and you can just plug them into the wires you removed and the other end into the sensor, or you can just plug the wires you removed into the pins of the sensor, If your a/c freezes up just turn the stupid thing off for a couple of minutes and it will defrost. Edited August 20, 2016 by mad1macs 0 Quote Link to comment Share on other sites More sharing options...
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