Do I need an Alternator upgrade?

[mavtricks71]

Hey guys i have a 1986 K10 and the engine I bought came with a cs130 105 Amp Alternator. My truck is originally an A/C truck so i think the original alternator is 78 amps? Is it necesary to upgrade the alternator? no electric fuel pump, no electric fans It just has 2 6x9 speakers and two 8 inch subwoofers with an Amplifier.

 

[75gmck25]

Doesn’t sound like you need it. I’m using a 94 amp 12si right now, and never see any evidence that it’s not enough. I added the relay wiring kit to my headlights, which was the only high amperage thing on my truck.

Higher amp alternators are needed to support big driving lights, high amperage sound systems, etc.

 

[fast 99]

Doubt it, our company had several SB tow trucks that used quite a bit more amperage than stock applications. Beacon light bar alone was 30 amps, jump starting other vehicles, flood lights, electric winch on 2 of them, never ran out of power. Only modification was a second battery and on one truck we used a smaller diameter alternator pully. Might consider a second battery, otherwise stock is plenty adequate.

 

[mavtricks71]

Thanks guys Illl just use my original Alternator..... Do you know if my truck is a 63 amp or 78 amp?

 

[75gmck25]

I assume that by ‘86 the 94 amp was common. However, even the original 63 amp on my ‘75 was an option upgrade that I think was included with A/C.

The 10si maxed at 63 amp, so if you have a 78 amp it is a 12si. Both will mount and wire in the same. Take a look at the madelectrical.com site and you can see how to identify what you have.

 

[sidschev]

if ya gotta ask then yes upgrade ,,,,,,thats my story an im sticking toit ...................

 

[Snoots]

The newer ADxxx models provide more umph at lower rpm's. If it works tho, don't fix it.

 

[SirRobyn0]

Running a stock 78 amp alternator. Keep in mind when talking about up grading alternators, the higher the amperage the greater chance of slipping the belt in a situation where the battery is very low and the alternator has to charge it up.

 

[Matt69olds]

I swapped a 105 amp CS alternator onto my Olds 20 years ago, I have never slipped the belt.

The alternator came with a pulley for a serpentine belt. I was kinda worried about belt issues when I swapped to the V belt.

 

[SquareRoot]

Running a stock 78 amp alternator. Keep in mind when talking about up grading alternators, the higher the amperage the greater chance of slipping the belt in a situation where the battery is very low and the alternator has to charge it up.

Convert to sprockets and chain drive.

 

[squaredeal91]

Convert to sprockets and chain drive.

Cogged belt/pulley

 

[Frankenchevy]

How many watts total in the sound system? 78 amps x 14vdc is ~1100watts. Obviously you aren’t running at full power all the time... 8” subs vary from 150ish watts each to 750+ watts each. 6x9s can be up to 200 each.

I’m doing a pretty low key SQ system in my 3rd gen ram that’s 3000 watts. Upgrading wiring and the alternator is a must when adding decent loads on a vehicle.

 

[Frankenchevy]

Convert to sprockets and chain drive.

Cogged belt/pulley

Gear drive.

 

[mavtricks71]

How many watts total in the sound system? 78 amps x 14vdc is ~1100watts. Obviously you aren’t running at full power all the time... 8” subs vary from 150ish watts each to 750+ watts each. 6x9s can be up to 200 each.

I’m doing a pretty low key SQ system in my 3rd gen ram that’s 3000 watts. Upgrading wiring and the alternator is a must when adding decent loads on a vehicle.

Honestly i havent added up the watts ...6x9 jl Audios and the 2 8 inch subwoofers but not sure on the brand an then im running the amplifier but cant remember how much power it has

 

[Frankenchevy]

Honestly i havent added up the watts ...6x9 jl Audios and the 2 8 inch subwoofers but not sure on the brand an then im running the amplifier but cant remember how much power it has

An average 8 will be 150-250w and an average 6x9 will be 75w. The 6x9s may even be ran off the head unit.