battery dies when a/c is on

[stykthyn]

when I run my a/c while I am driving I can literally watch my voltage drop. does this sound like a bad alt?

 

[cjones]

do you have underdrive pulleys on??

what is the voltage?? 13.5 - 14.5??

have the alt and charging system checked at a good parts store. most can check it on the car.

 

[HISSIN50]

Also tell us if the voltage drops that much from having the AC simply on, or if it's from having the AC on AND having the HVAC fan running on high or one level below high. Also, how does it do while RPM's are higher than idle?

It is possible you dropped a diode - high load charging takes a fat doo-doo when this occurs. The parts store test will show that (even the dynamic test they do curbside at your car can often detect this).

Good luck.

 

[stykthyn]

It drops while I am moving. I can understand if it was at idle as I still have the stock alt, but when I am doing 65, it should be cranking out more than enough current. the needle is usually at he 1/2 mark or a tad higher, but when the a/c clutch kicks on it plummets like a rock. My stereo cuts out and my guages freak. This happens regardless of rpm, so that is why I am leaning towards a bad alt.

 

[93 LX]

sounds like you have a bad short in the clutch circuit or a bad clutch itself. Remember the clutch is a magnet which ic a coil of wire. If the coils are shorted together it will draw a ton of current thus killing your charging system.

Allen

 

[stykthyn]

alrighty guys I just completed the 6g alt swap and this thing runs like a champ. no more drainage issues at the moment.tomorrow we'll see if they stay gone. thanks for all of the input.