AC Pressure Switch

Don't do it again because you are ground the A/C circuit. Why do you want to jump the pressure sw, low on refrigerant??

No, I am filled up with refrigerant. My ac system is new. I just wanted to see if the electrical system is malfunctioning...I was told that if my fuse blows when I jumper the switch, then it means I have an electrical issue and that is the reason why my compressor wont come on. I put a jumper wire from the battery's + terminal to the electrical connector on the compressor and I heard the clunk sound from the compressor kicking on so I know that is good. It just won't come on, and I am not sure at this point why? I need an idea of what I need to look for next....

For us to be able to assist you, it is absolutely necessary for you to include the make, model, year and mileage of your car.

When you do this I can help with the problem

Sorry about that...It's a 1995 Saturn SC2, 177k miles.

Your car has an HVAC module which is the control head in addition there is an air temperature. These signals go to the ECM which provide the signals for the compresor to come on.

I have troubleshooting charts if you need a copy let me know.

Mr. Parmeter,

Please, if you could give me a copy of those troubleshooting charts, I would be very appreciative...Thank you. Also, I pulled a code from my Saturn yesterday and it was a code 26, but the manual I have for my car doesn't have that code listed, it is a little upsetting. Would you happen to know what the code is? Once again thanks...Garrett D.

Code 26 is a Simtec code that has to do with the vehicle speed sensor.Do you have a speedometer problem or a transmisson shifting problem??

How did you get the code? Counting flashes are not accurate.

I will copy the troubleshooting charts sometime today and send them via E mail.

I got it by counting flashes. I believe it has something to do with my AC not working, when I read the link for trouble shooting the DTC 26, the section that applies to my situation is that when I ground the ALDL A to B, coolant fan kicks on instantly. Then it tells me to remove the ALDL ground and turn on the car and run the AC. I know my AC doesn't run, my compressor doesn't kick on. Therefore, the trouble shooting guide says to check for grounds. I have a digital multi-meter, I wanted to know if there is a way to check the plug holes that my AC relay plugs into with the multimeter? Otherwise, how do you check a relay for resistance. What prongs do I test out of the 4? In addition, is it true that if I get to my PCM and try to take a look at the wiring and unplug the connectors will I have to go to the dealership and get it reprogrammed? I am a little hesitant about messing with the PCM if that is the case. How far in handling the PCM can I go without having to reprogram it?

Before you get to involved have you tried replacing the AC relay with a known good one?

yes. And I know my clutch works because I have, put a direct line to it from the pos terminal and heard the clutch "klunk" in the compressor.

Check your E mail I sent the troubleshooting flow charts.

Hello Mr. Parmeter,

I didn't get the charts attached with the email you sent...if you are able to, can you try to send them again for the 1995 Saturn SC2? Thank you, I appreciate it... Garrett D