Stock alt size for '82 J20?

[SmokinStanley]

Hey Folks,

Just picked up an '82 J20 that's a stock rig. I'm in the process of modifying the charging circuit -- directing alternator current to starter solenoid and connecting the large 10 ga. wire that feeds the 'main' power supply to the interior to the start solenoid as well. I'd like to add circuit breakers to the new 6 gauge cable I'm going to run between the alt. power output and the starter solenoid, and I'd also like to add a breaker/fuse to the red 10 gauge wire that feeds the interior.

Anyone know the size/output of the stock J20 alternator for 1982? This is a non-A/C rig. Also, I'm looking for recommendations on fuse size for the main red 10 gauge feed to the interior. I'm thinking 40 amp would be appropriate for the red wire that feeds the interior, but not sure on the breaker size I should use for the new wire that will come off the alt. and connect to the starter solenoid.

[serehill]

If it were me

I would use auto reseting circuit breaker on the#10 wires that is correct. Yes 40 amps I would simply buy a 2 foot cable & run it from the alternator to the solenoid. The one you can buy at any auto store that looks like the wire that runs from your solenoid to the starter. You know th eone with the eyes already on them. Keep it out of harms way & you won't have to fuse it. I have 2 done that way the Cherokee has been that way for 7 years. your alternator should be a 67 amp that's the right wire. #4 copper. You can use #2 but you don't have 2.

[SmokinStanley]

OK, thanks for the quick response. So, if the only modifications I make are a) moving the 10 gauge wire from the alt. output to the hot side of the solenoid, and b) installing a 4 gauge wire between the alt. output and the hot side of the solenoid, I'm sending the primary amperage of the alternator directly to the battery, yet maintaining the main power feed from the red 10 gauge wire to the interior?

What I'm also trying to wrap my head around is whether the ammeter will still read properly if the original red 10 gauge is now connected to the hot side of the starter solenoid and fused at 40 amp. If I leave the yellow 'return' wire alone, I'll still have a power loop going through the ammeter, only with a 40amp limitation. It seems that setting up the wiring this way will allow me to keep an ammeter in service for a stock look (even if it's limited by a 40amp breaker), yet send more of the amperage load directly from the alternator to the battery via the new 4 gauge cable. Does this sound correct?

From what I understand, the alternator sense wire is spliced into the yellow wire, so I'd rather leave the yellow wire undisturbed in the circuit and keep the ammeter wiring intact. I already know the connections at the ammeter are clean and tight, so I'm confident the ammeter can stay in service. Just trying to figure out how true the ammeter readings will be if the original red 10 gauge 'interior' feed is now sharing the same post on the start solenoid as the new 4 gauge wire coming from the alt. output