[Rich-L79]

The truck still has it's original (rebuilt by me) 37 amp alternator. It was built as a plain-jane low option truck. Electrical add-ons include electric trailer brakes, an aftermarket stereo (it originally had an AM radio) and some aftermarket gauges but the only electrical draw there is the lights for the gauges.

I recently added air conditioning. Everything seems to run fine and the alternator doesn't seem to be getting overly hot but I'm wondering if the AC may be pushing the alternator too hard. I imagine it would cost less than $40 to buy a good rebuilt (non-internal regulator) rebuilt alternator with more amps just to be safe. I could always throw the old but still good one in the trailer box as a traveling spare.

Am I just wasting money on an alternator upgrade? If I should upgrade how big of an amp rating should I shoot for? Is it just a direct bolt in swap, I wouldn't need to change the voltage regulator would I?

TIA.

 

[John_Muha]

Pretty much the same thinking as the Chevy engineers found. My 64 with A/C came with a 37 amp, but in later years they boosted it up to 61 for the A/C models. The 37 amp units don't charge well at idle with everything on.
You won't need to change anything else if you go to a higher output external regulator (DN) model.
http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi?ubb=get_topic;f=22;t=002491

 

[68KMENO]

John right as usual

the factory went with a 63 amp in the same casing as the 37 amp for the AC upgrade in the loaded cars... which should be enough -IF-you don't have a KILLER STEREO or electric fans .. its is a direct bolt in which makes it nice .. cars with LOTS of electric stuff .. well the 12si is the way I'd go but its more work & won't look stock anymore IF thats important