alternator and radiator question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**old Rusty C10** · 08-18-2011, 06:51 PM

on a truck with a 350 motor and 350 automatic trans with air conditioning, I should have what size radiator in there?
also for that kind of truck i should be running a heavy duty alternator? I notice with the air conditioning on the truck and radio and even worse when i have on the lights or wipers the truck idles and the alternator guage dips down to about 8 then its just under 13 while moving
im thinking that i should put in an alternator that is at least 100 amps

tucsonjwt · 08-18-2011, 07:07 PM

As long as your truck starts OK I would not change your alternator. I put in a 160 amp alternator and it did not change the reading on the alternator (about like yours). If you have mega blaster amps and boom box then you might need a higher output alternator. The stock alternators are like 64 amps and seem to do the job fine. I think the gauges are only approximate in their readings anyway. A/C will drop the output but should not affect the state of battery charge over a long time period. I have also read that higher amp alternators require larger gauge wiring.

08-18-2011, 06:51 PM	#1
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,310	alternator and radiator question on a truck with a 350 motor and 350 automatic trans with air conditioning, I should have what size radiator in there? also for that kind of truck i should be running a heavy duty alternator? I notice with the air conditioning on the truck and radio and even worse when i have on the lights or wipers the truck idles and the alternator guage dips down to about 8 then its just under 13 while moving im thinking that i should put in an alternator that is at least 100 amps __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

08-18-2011, 07:07 PM	#2
tucsonjwt Registered User Join Date: Jul 2007 Location: Tucson, AZ Posts: 3,189	Re: alternator and radiator question As long as your truck starts OK I would not change your alternator. I put in a 160 amp alternator and it did not change the reading on the alternator (about like yours). If you have mega blaster amps and boom box then you might need a higher output alternator. The stock alternators are like 64 amps and seem to do the job fine. I think the gauges are only approximate in their readings anyway. A/C will drop the output but should not affect the state of battery charge over a long time period. I have also read that higher amp alternators require larger gauge wiring.



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