Overcharging battery -- almost there

[JG1966]

I have been chasing an overcharge on my 72 340 RR for a while. Got lots of help from you guys but I'm now officially stumped.
I was charging at 15.5 at idle and had 1.50 voltage drop from battery positive to blue alternator wire. I got it down to 14.95 and 0.9 drop after cleaning and going through entire circuit.
I have a .25 voltage drop at the blue wire at the bulkhead engine side (which is exact same drop as my ignition switch drop when I isolated that for a test)
But.... I now have a .32 drop from battery positive to blue alternator wire (not too bad) and a .60 drop from battery positive to blue igniton wire at voltage regulator. YET I AM STILL CHARGING AT 14.95
Any ideas or suggestions? Thanks

 

[bm02tj]

Only three things
Bad alternator
Bad regulator
Bad connections and components supplying bad info to regulator

 

[Demonic]

Check the volt meter against another one maybe.

 

[JG1966]

Only three things
Bad alternator
Bad regulator
Bad connections and components supplying bad info to regulator

Thanks BM. I know the regulator is good. The connections are much better now. The alternator I guess could be an issue, but it's passed every test. What has me confused is that every time through this process that I reduced my voltage drop at the blue alternator wire or ign 1 wire at regulator, I ALWAYS got a corresponding drop at the battery. This time I dropped from .90 to .32 at the alternator, and battery didn't drop at all. If it matters, my large alternator post is also showing same as battery, 14.95.

 

[JG1966]

Check the volt meter against another one maybe.

Thanks Demonic. I have tried two voltmeters and both say the same

 

[72RoadrunnerGTX]

Have you checked the voltage drop across the ignition switch Molex connectors, specifically the Ign1 and battery feed terminals? If you can’t get the total voltage drop to where you want it, you could try an adjustable voltage regulator, dial it down a bit to compensate for the reference voltage difference.

 

[JG1966]

Have you checked the voltage drop across the ignition switch Molex connectors, specifically the Ign1 and battery feed terminals? If you can’t get the total voltage drop to where you want it, you could try an adjustable voltage regulator, dial it down a bit to compensate for the reference voltage difference.

Thanks 72. I got a .28 drop from battery positive to red wire Molex and a .48 drop from battery + to blue wire Molex. I also got a .25 drop when I tested ignition switch (probes on blue and red Molex wires on ignition switch side). I will check out the adjustable voltage regulator. I've driven for five years with this overcharge and never had an issue (and I've brought down number quite a bit), but I'd like to get it lower.

 

[72RoadrunnerGTX]

The Molex connectors at the ign switch has been a problem since they where first used in that application. Resistance and heat build up is common at those Molex terminals. I replace those Molex connections, with better quality and correctly current rated Anderson Powerpoles, and or by-pass any other disconnects in the ign1 circuit to get the total voltage drop as low as possible. I will by-pass the ign1 bulkhead connection as well. Another step I’ve taken on some cars is up-sizing the ign1 wiring to the VR to 12ga.

BTW, if you take your drop measurement on each side of the Molex terminals while under full load you can see just what specifically the Molex terminals are contributing to your total number.

 

[four40cuda]

Following. I am fighting a overcharging issue in a 1968 Bee. Almost the same exact issues...i need help too..lol

 

[JG1966]

Following. I am fighting a overcharging issue in a 1968 Bee. Almost the same exact issues...i need help too..lol

Hope you find it. Lots of smart people on here. What are your voltage drops? What are you charging at?

 

[BLK 68 R/T]

Is your regulator itself grounded to the body with a good clean ground?

 

[JG1966]

Is your regulator itself grounded to the body with a good clean ground?

Thanks BLK. Yes. Getting .01 drop from battery negative to voltage regulator case. All grounds are all good