Charging system diag

[64furyous]

Hey everyone,

I am scratching my head on my charging issue.

For some background, I've owned this car less then 6 months and it's been one thing after another so far. The car is a 1964 fury with a 440. The charging system is a square back alternator and from the research I have conducted it has a round back voltage reg (c8010-1). I am not sure if that has any relevance in my issue.

I have recently added a holley red electric fuel pump because my cam decided to eat itself on a recent trip. Along with an electric pump, I also have a single 16" electric fan.

Took the car for ice cream last night and upon restarting the car it was stone dead. Had a buddy come and boost and made it home no problem.

Tonight I am deep into diag and I'm not sure what to make of my results.

I know my alternator is functioning properly and from what I can tell my voltage reg is as well. Before I start ripping harnesses apart and getting deep into it I thought I would ask you guys if you have any input.

Key off:
12.7v batt
12.7v alt
0v fld
0v ign

Key on:
12.6v batt
12.45v alt
1.5v fld
0.5v ign

Idle:
12.6v batt
13.9v alt
12.1v fld
13v ign

1500rpm approx:
12.9v batt
14.8v alt
8v fld
13.8v ign

Thanks,

 

[jimbosride]

Maybe battery drainage is due to a fuel pump that is stuck in the closed/on position. ????

• Relay kit P/N 12-753 & 7 1/2 amp fuse recommended ???

 

[64furyous]

Maybe battery drainage is due to a fuel pump that is stuck in the closed/on position. ????

• Relay kit P/N 12-753 & 7 1/2 amp fuse recommended ???

Thanks for the reply jimbo.

I installed the pump using the Ron Francis FP36 wiring harness.

I'm thinking that the car has always had this charging issue and now that I have added more draw to the circuit it is unable to maintain enough charge. I originally thought about ordering a new alternator and regulator but I hate throwing parts at stuff. Especially because I have potential big plans this winter for the car.

 

[jimbosride]

I hear ya.... maybe charge up the battery then unplug the pump and see if the battery is dead the next day. You should also be
able to check for a draw while the ignition switch is off.

That looks to be a nice harness so it should do the job

 

[64furyous]

I hear ya.... maybe charge up the battery then unplug the pump and see if the battery is dead the next day. You should also be
able to check for a draw while the ignition switch is off.

That looks to be a nice harness so it should do the job

I checked across my ground side. I have 7.5ma draw that doesn't change when I pull either the fan or pump fuses. It's always started fine and had adequate voltage except for the other night when it wouldn't crank after I shut it off in the drive thru.

I also made a jumper wire and jumped across my fld and positive post during my diag earlier. I didn't write it down but I believe it was in the 14.5 range, I expected it to be higher given that I was essentially bypassing the voltage reg.

I essentially have a 2v drop from my alternator to my battery.

I am not sure my next step but I suppose I will sleep on it. Looking through my manual it appears it goes alt-lightswitch-ammeter-starter-battery. Guess I'll start checking drops across that circuit.

Thank you for your assistance

 

[Don Frelier]

There should be almost no voltage difference between the alternator charge terminal and the battery.
I would check the bulkhead connector where the charge wire goes into the passenger compartment.

 

[64furyous]

There should be almost no voltage difference between the alternator charge terminal and the battery.
I would check the bulkhead connector where the charge wire goes into the passenger compartment.

I plan on checking the wiring from my alternator to the battery along that circuit and tracking down my voltage drop after work today. Ill start at the bulk head connector. Thank you