Charging system close to max?

[383man]

First thing I would do is check the charging system and see how many amps the alt will put out. Even though you have a voltmeter on the circuit you still need to know the alt amps to diagnose the charging system. What is the rated amps of the alt on the car ? It seems to be charging but not as well as it should. I have even seen battery's take in many amps but not bring the voltage up when there was a battery problem. When I had the stock 35 amp alt on my 63 it would drop to about 12.5 at idle at night with the electric fan and headlites on. But as soon as I hit the gas she came right up to about 14.2 and styed there unless back at idle with all loads on. I switched to a 100 amp alt so it will now charge enough even at idle to keep battery volts at 14.5 with all loads on at idle. I would definetly check your alt amps output at 1800 rpm with all loads on and see what it is putting out. Ron

 

[Canadian1968]

Well to update this.

I finally ran the power directly to the alt. stud as suggested . Warming up everything is fine . Battery 14V , when the fans kick in battery drops down to 13.5 but my alt. was actually at 12.5 !!! Thought that was kind of weird . I turned on lights and that's when it started to struggle . The Alt was reading 12.2 and would dip into 11s a few times
Something is up. Is it the alt. or the regulator .

The amp gauge is dead center so I'm. guess it's not picking up the draw of the fans since it's right off the alt. stud .

 

[72RoadrunnerGTX]

...when the fans kick in battery drops down to 13.5 but my alt. was actually at 12.5 !!!

This describes a 1 volt voltage drop in your charge output circuit. To verify, connect one lead of your VOM to the alt stud, the other to the positive battery post while under load. Sounds like some high resistance at some of those charge circuit connections.

The amp gauge is dead center so I'm. guess it's not picking up the draw of the fans since it's right off the alt. stud .

Ammeter should not register any vehicle loads while running. A discharge reading indicates the alternator is not keeping up with total loads.

 

[Canadian1968]

Well it's seems to be fixed !?

I took the alternator to a local shop and had them test it . They told me its working great and its a 70 amp .

Went home and I pulled out the relay I am using and tested it , everything was fine . Put the alternator back in and want for a drive arounder the block to warm it up. Got out tested battery 14V . The fans kicked on and it dropped to 13.56v . Went over to the alt. 13.56V . Let do a fan cycle and it didn't drop below 13.5v

So only thing I can think is maybe one of the connections to the relay were not fully seated ? But everything seems to be fine now.

Wow what a headache lol that calls for a beer