Does the starter cable get hot when it's trying to turn over ?

 

Not to try to hijack but I have a somewhat similar issue with my '76 with a 390 FE and maybe whatever your issue is is similar. When I first got it, the battery that was in the truck wouldn't turn the engine over even with a jump. I've swapped engines, and on my 2nd new die hard gold battery 750 CCAs and it will still go completely dead in 2 weeks. About the 9th of this month I swapped carbs and did a fair amount of cranking getting the bowls full, then just got the idle adjusted and diddn't really drive it because I had it apart for ball joints. Then a week later I go to start it and the battery has like 7 volts.

MAYBE there's a draw somewhere but I can't Imagine where as I've gone through all of my grounds and you can touch the negative cable to the battery post and there's not even a tiny visible or audible spark at all. When the battery gets too low you can have another running vehicle attempting to jump it and it won't be able to turn the engine over without sitting there charging for quite a while. If I start it like once a week at least it's ok but I'm still kind of lost too as to what could cause this. Corroded solenoid internals maybe? Battery cables are new. There was a lot of wiring hackery when I got it, especially for the tail lights (they were running off of the brake pedal switch power) but I've fixed all of that and added new/additional grounds.

 

You need to get a multimeter and check for a parasitic draw.

 

I do have a little fluke multimeter, but no ammeter. I need to finally splurge and buy one. I just figure if I have a draw and a spark won't even jump from the battery terminal to the cable it must be very small, but I guess it could still drain over a week or two.

 

You should really start your own post as not to get the OP off track with your issue but .......

Forget the meter get a test light, not a LED one. Fully charge the battery with the cables removed.
You did not asy the battery will hold a charge if the cables are not hooked up?
Once charged hook up the POS cable as normal but on the NEG cable put the test light between the battery and the cable.

If there is a draw the light will light.
Little draw the test light will be dim, big draw bright light, pretty simple no?
Now note with the doors open the dome light may be on and cause the light to lite so close the door between this next part.
If you have a modern radio it can also be a little draw.
Remove 1 fuse at a time checking the test light till it goes out. Even just a little dimmer on the light will tell you where you need to look.
If the fuse is for say stop lights you know that the stop light area / wiring is where you need to look for the draw.

And using the test light you can look at the light from the door and not need to get out and go look at a meter.
Work smarter not harder.
Dave ----

 

This is consistently the voltage regulator in my experience

 

Now that I have 3 brand new batteries the newest one has started it

 

By itself not with all 3 wired together O'Reilly's will have to check the other 2

 

90% of the time it's the battery. you need a better one with higher amps but one battery should do it easy.

If you have 2 batteries and one is bad it will draw the other down.

 

I tried them separately and as stated they were new one bought and then when that didn't work then the second to replace it then just both

 

not to keep ****ting up your thread, but when I put in a one wire alternator I just used the existing output wire and the stock voltage regulator hasn’t been removed, it’s just sitting idle still attached to the harness. That’s a good thought, I should probably clean that up.