Overcharging

[RCCDrew]

Going home today my voltmeter hit 18V. Pretty much verified because at the same time the belt started squealing slightly and the gauges were freaking out. I unplugged the field wires and drove home with no problems. New voltage regulator. Could the problem be the alternator? Any ideas to other causes?

[GoodysGotaCuda]

Unfortunately the "new" voltage regulator can certainly be the problem, if it's a typical parts house part, it would buy another to validate the issue persists. Ensure the VR has a good ground. You should also check that with the "key on", the VR 12v wire does not have excessive voltage drop. You should see minimal voltage difference from the battery to the VR, otherwise it will think the battery is lower than it really is [typically not by 4v+ however].

[duodec]

Specifically check that the regulator case has a solid ground, and you have solid grounding from body to engine and battery negative.  If it does not then alternator voltage can float.

[RCCDrew]

I hope the new VR isn't the problem. It's doing the exact same thing as the old one. Its the "high quality " part if that makes a difference. It's weird in that it charges fine for a while and then all of a sudden it goes high voltage. Lots of times it will flicker between high voltage and normal voltage. I'll check my grounds and see if that helps. I hate that the problem usually shows up halfway into a 20 mile trip.

[Bullitt-]

Don't overlook Goody's advice... Intermittent poor connection on the Blue wire can cause this as well

[734406pk]

Another option is a quick and easy DIY single wire alternator conversion using the TRANSPO D7018 piggyback regulator instead of the oem unit. Here's a link for the kit:::

http://store.alternatorparts.com/partnod7018.aspx

14.2 volt regulation. 

[RCCDrew]

Another option is a quick and easy DIY single wire alternator conversion using the TRANSPO D7018 piggyback regulator instead of the oem unit. Here's a link for the kit:::

http://store.alternatorparts.com/partnod7018.aspx

14.2 volt regulation. 

I have one of those! Wonder if I can find it.

[734406pk]

This will take some load off of the ignition circuit plus eliminate overcharging due to voltage drop- sensing is right off of the alt output terminal. Good Luck!!

[dodj]

the VR 12v wire does not have excessive voltage drop.

That is what caused my overcharging issue a few years ago.  Check your valve cover connector and fusible link connections. If you have not done the 'ammeter' wiring change, the condition of your bulkhead connector needs to be checked/cleaned as well. My car was charging at 16.8 volts. After I cleaned up all the connections involved with the voltage 'sense', it dropped to 14.2

[RCCDrew]

Another option is a quick and easy DIY single wire alternator conversion using the TRANSPO D7018 piggyback regulator instead of the oem unit. Here's a link for the kit:::

http://store.alternatorparts.com/partnod7018.aspx

14.2 volt regulation. 

I found it!  But I can't remember how to wire it up. Any instructions?

[734406pk]

I found it!  But I can't remember how to wire it up. Any instructions?

Red B+ to output terminal. Red spade connector to one of the field connections (doesn't matter which one). Black to the case for ground. Green spade to the other field wire and blue gets connected (ring terminal or solder) to the stator output before the diodes inside the alternator. The reg should come with instruction if you buy the conversion kit. 

[RCCDrew]

Red B+ to output terminal. Red spade connector to one of the field connections (doesn't matter which one). Black to the case for ground. Green spade to the other field wire and blue gets connected (ring terminal or solder) to the stator output before the diodes inside the alternator. The reg should come with instruction if you buy the conversion kit. 

no, I didn't buy the kit. I had it laying around after I took it off an alternator. So I have to split the case to get the blue wire on?

[734406pk]

Yes. The blue wire attaches to the stator AC output and that is what switches on the regulator. I don't remember if you have to solder or a ring terminal will work. It was pretty simple though.

[RCCDrew]

I got it! I was able to look at the old alternator and figure out how it went together. Thanks for all the help with this. I'll put it back together and let you know if it worked or not.

[734406pk]

Good luck!