Charging issues with New 440 in 73 Roadrunner

[adk-roadrunner]

How's it going. So as the title states I'm having charging issues and it actually left me stranded twice in the same day once because it wouldn’t start at the pump and the other because it stalled at an intersection after being in slow traffic for a while so I'd like to get it figured out so I can enjoy the car again. The car is a 1973 Roadrunner that was originally a 318 but I swapped a 440 I built into it. when I built it I installed a 440 source engine front end kit that came with a new alternator. Most of the engine build doesn't matter I think but it does have a pretty lopey idle with the comp nostalgia purple cam I have in it. I added Edelbrock E Steet EFI with the remote fuel sump system with the high pressure pump built in, and I'm also running dual Spal fans that the ECU controls. I do also have a custom autosound retro stereo with an amplifier in the trunk.

I did notice recently that on my phone that is bluetooth'd to the ECU that when the car is idling while parked or in traffic it really doesn't seem to be charging at all and is actually losing battery power. I did some testing and what I found today is that if it is charging at idle I'm only seeing .3 to .4 volts at battery higher with alternator on for a reading of maybe 12.5v or 12.6v at battery and this is with no fans running as I didn't have time to let it heat up. I also tested directly off the lug on the back of the alternator and I'm seeing around 13.5v so I'm losing a volt or more by the time it gets to the battery. I also tried grounding the field lug on the back of the alternator and it doesnt go higher than 12.9v at battery or 13.8V at alternator lug. I tested 2 voltage regulators as well the old original and a new Mopar unit I bought from Year One and have come up with the same results.

Any help or Ideas of waht to check would be appreciated Thanks.

 

[Daytrepper]

Is your main alternator wire going direct to the battery or does it go thru the factory wiring into the dash and ammeter?

 

[adk-roadrunner]

Is your main alternator wire going direct to the battery or does it go thru the factory wiring into the dash and ammeter?

Through Factory wiring.

 

[Daytrepper]

Through Factory wiring.

First place I'd look is the bulkhead connector where the alternator wire passes thru, and see if its melted; next place to check is the ammeter. There is probably a poor or melted connection somewhere causing a voltage/amp drop.

With running accessories like the fuel injection, sound system, and fans, I would bypass that and wire the alternator directly to the battery with a fuse. See what kind of shape the wire going thru the bulkhead connector is and repair it; and install a fuse once you bypass it. The other thing I would do is bypass the ammeter gauge and have it converted to a volt meter (redline gauge works) unless you can stand it not working on the dash.

This is assuming too that regulator is new and wiring to it is good. Thats the next thing to check.

You could also upgrade the alternator to an internally regulated one wire setup with higher amp for the accessories you have.

These old systems weren't necessarily built to handle many accessories running and especially with poor connections there can be alot of problems -- even fire.

 

[pnora]

Run a HD temporary jumper direct from the alternator stud to the battery and then see what the alternator does. If you full field it and it is still low I suspect alternator problems.

 

[Daytrepper]

Just went thru this on a buddy's 74 model, this is what we found: