I've been having some wierd electrical problems lately. This time I go in my car and turn on the A/C... it comes out really warm, check the pressure on the low side and its around 140psi (yes it def. was the low side and my A/C was running on max)!!!!!! (I remind you the air was blowing cool in the morning). My voltage gauge is in the red and my check gauges light is on. I just checked my battery and it read 12.29v then I started the car and checked it again and it read 3v and fluxuated every second (1 time it hit 11.99 then went right back down to 3v). Does this sound like a bad alternator... can a lack of electrical power cause my A/C to not turn on (therefore giving me the extremely high PSI even when the A/C is turned).



//Mark

 

I've never seen an alternator cause an AC compressor problem.

The first thing to check should be having the PCM scanned and see if there are any codes that would cause the system to not allow the compressor clutch to engage...

Sounds like the compressor clutch is not engaging... I had a similar problem last summer where the low pressure sensor switch was tripping a code that would do that... I could clear the code and the problem would go away for a while... I ended up replacing the sensor and haven't had a problem since...

 

I would think the alternator pulses so it doesn't overcharge batteries. I'm only guessing.

 

The first thing I would check would be the battery cable connections.

 

When the car is running, the reading at the battery posts should be 14 to 14.4 volts. I'd check the connections and make sure they're free of corrosion, and also the connections on the back of the alternator. There should be the charging wire that goes to the battery/distro block, and also a little wire with a weatherpak on the bottom. This is the regulator wire. If it's not plugged in, it won't charge.

 

Had the alternator tested at autozone... that was the problem. It had a lifetime warranty so I got another for free. Installed it and even the A/C problem was fixed, now it is blowing nice and cool. Thanks for all your help.


//Mark

 

Well that's good news! We all came away with a little more knowledge. Thank you for sharing. Good luck with the Autozone alternator....