KenSny

I'm getting ready to upgrade my SI-10 61amp alternator with the Quick-Start upgrade kit that will take it to 105amp.

Has anyone done this - and - did the stock AMP (BATTERY) gauge work ok? I have seen a post or two about "frying the gauge".

Budman68

I'm running a 100 amp alt and the guage works great. Not sure where the problem would be. Becareful on high output alts, you system is not built for the load and bad think can happen. By the way, why do you need that many amps?

KenSny

Don't really need 105amps, would rather go to 80, but the only upgrade I can find is for 105. And I'd really like to just upgrade the existing unit instead of buying a new one.

KenSny

ttt

A C

How much does the upgrade cost? I just picked up a brand new chrome :cool: alternator (not rebuilt) from Summit for just over a hundred bucks. It's a 100 amp alternator too.

AC

KenSny

$39.95 + a couple of bucks for shipping of the parts.

mrvette

You will NOT fry the gauge, as it's in series from battery + to regulator input, and the amount of currents there are minimal at best....

GENE

KenSny

Thanks, that makes sense.

SteveG75

Ken,
http://www.alternatorparts.com

80 Amp upgrade for $24.95

KenSny

Steve - #7001 is what I thought too. But, I called them last week and they said that kit #7011 was the only one that fit my stock 61a alt. Now I'm really confused. Guess I'll call again and maybe get to talk to someone different.

mrvette

Look, go to Auto Zone or some such place with ignorant counter help, and just BUY outright a 108 amp unit, pay the core charge, later on return the core for cash credit.....thay don't know to check ratings....but if they sit next to each other, the 108 amp unit is slightly larger in diameter so may prompt them to check #s.....

GENE

KenSny

The point is, I can upgrade the unit I have for less than buying rebuilt or new.

dladd74roadster

Ken,

I can't remember if a 75 has a Voltmeter or Amp guage. If it has an Amp guage, you wouldn't want to run it with the new alternator. The 40 amp guage won't handle the 105 amps of the new alternator. If you have a voltmeter, there are no problems.

dl

rainman69

I'm kinda confused, but maybe I was asleep during this part of my power systems class...

An alternator will only provide as much current as needed (unless it's broke somehow). If you're on the positive side of the gauge, that means that the alternator is supplying more current than normal to recharge the battery, if you're on the negative side, the alternator isn't supplying enough for the load.

I can see how if for some reason you were drawing 100 amps by charging the battery and supplying the car loads, maybe you could damage the ammeter. Just remember that my '69 with A/C came with a 60+amp alternator (I don't remember exactly the rating)...and a 40amp ammeter.

Now, when it comes down to it...caution and carefulness are always key...but it doesn't make sense to me that an alternator can over-current a system unless it goes bad.

mrvette

Look, anyone who glances at a GM wiring diagram will see the ampmeter hooked in series from switched +12 to the sense wire input of the regulator.....go look at say a '72 vette schematic....that's the way they are hooked up, the main power does NOT go through the ampmeter, as in a more simplistic way of thinking....so any alternator will work with that system, and there is NO WAY of blowing the ampmeter....period....

now an old tymey thinking would say put the ampmeter in series with the load,....but GM found a way around that probably to save heavy wiring and for safety reasons too.....corrosion, resistance, fire, heat, all kept under the hood....