Gary79

if i change to aluminum radiator with electric fans will i need a 100 amp alternator??? my 79 vette has ac, rear window defroster, power locks windows, and power antennae, 700r4, am/fm/cassette. the stock alternator is about 60 amp, I think. where can get a 100 amp alternator and is a just a bolt on change??? Thankx!

1979toy

I've got the same equipment as you except for the 700R4 and have not upgraded my alternator. Been working fine for over a year. I don't use the radio or rear defrost very much though.
Your local auto parts store should be able to help you locate a 100 amp alternator that will be a straight bolt in and plug in change. If they can't help then a P/N PWM-17802 from http://www.summitracing.com should do it.

Fast81

Gary, fellow forum members turned me on to this website when I posted a ? similar to yours a few weeks ago. MUCH cheaper just upgrading your working Alt than shelling out for a new one ($35 vs ~100-150).
scroll down to Part # HO 7011

http://www.alternatorparts.com/gm_al...grade_kits.htm


[Modified by Fast81, 2:27 PM 9/9/2003]


[Modified by Fast81, 2:27 PM 9/9/2003]


[Modified by Fast81, 2:28 PM 9/9/2003]


[Modified by Fast81, 2:30 PM 9/9/2003]

ROD NOCK

Yes. If you increase electrical load (accessories) you should offset it with higher alt output. An example: if you have an existing 60 amp alt, and you're adding an additional 30 amp draw, that would put you in the 90 amp range. You also want to leave a little head room for battery charging, etc...
You currently have alot of stock electrical options on your vette as it stands. I wouldn't skip the upgrade. Upgrading is more economical than purchasing a new unit. (Some good options listed above.)
Good Luck :chevy

Fevre

Summit had their 100 amp alts on sale, about $70 for a black one and about $100 for a chrome one. I bought a black when I switched to dual elec fans. If you got a stereo with even a small amp I would at least upgrade.

Bobchad

Does the upgrade require supplementing or changing the wires on the main output/charging circuit? Others have posted that it does as this wiring is only meant to handle the output of the stock alternator. Going from 60 to 100 amps is a 60 - 70% increase in peak power going through these wires.

Fevre

Good question, I did not upgrade mine so I'll be :lurk:ing .

Gary79

i think i'll do the radiator & fan thing and see what i get. a local guy rebuilt my original alt, so maybe he can upgrade it also. thanks fellas, good question about the wiring, i'll have to keep that in mind.

Maurice

I was wondering this same question. I came to the conclusion that since my radio and windsheild wipers, and brake lights don't work, I don't think I am taxing the alternator that is in there.

ROD NOCK

Quote:"Does the upgrade require supplementing or changing the wires on the main output/charging circuit?"

It depends on the margin of increase. Using my vette as an example. I'll be upgrading to a 100 amp alt. It currently has a 10 ga wire feeding the output circuit. I'm giving a bench measurement of a 10 ft run of wire on that circuit (until I actually measure it and round off high) for replacement. Applying ohms law, that requires I replace it with a 6 ga wire.
Some folks have upgraded the output amps, but not the wiring. That's their choice, and they may get away with it. But one of my motto's is: 'It's better to be safe than sorry.' I can't match the price of a piece of wire and the effort to install it against my vette, it's not worth it!!
The alt output circuit is one that is only protected by design, not fuses. So exceeding the stock envelope by a large margin is just pushing it over the edge!
You don't have to dig the old wire out of the harness. It can be replaced by disconnecting the old wire, connecting the new wire and running it in parallel with the harness. Wrapping it well to protect it is recommended!
Corvette electrical stuff, just keeps my headaches constant! :crazy: :lol: