1977 Monte Carlo.
Stock alternator, slightly larger battery.
Big 3.

0g Wire to distro. block, 4g to amps.

2 Kenwood KAC-9102D. 1700w each.

Legacy LA190 ( I think ), 400w.

Deck, Undercar neion.

Would a capistor/cap, help me, so I do not need to upgrade my Alt.

 

You don't say how big your alt is.

that system will draw close to 100 ampres. (your amps are 850 wrms @ 2 ohm)

i'd put a 3 farad cap in. i have 1 and a 2 f. with 140 amp alt in my monte carlo.

others here will tell you different, so asking about caps here, you'll get many opinions.

 

As posed the question is buy a cap or upgrade the alternator. A capacitor can never make power, that is what alternators do. So adding a cap can not ever make up for a too small alternator.

Now do you need a bigger alternator? You havent mentioned any problems so no dont upgrade either unless you need to.

 

I am unsure of the output on the alternator, it is a stock Chevy, for the older 305's.
Could I put a volt meter on the main power output on the back of the alt, and ground, to test the Amp output.

Secondly, I first had my system going a few weeks ago, and found my lights would dim. I then found one of my Kenwood amps, was not fireing up, and it is in to get repaired.