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Voltage regulator issues, broken wire thing
So I have been driving the car more often and a new problem has arose that I cannot shake and it's beginning to drive me nuts.

Few weeks ago my car started going crazy with wierd things with the lights so I checked the battery voltage with the car running and my guage read 18v..uhoh. So I shut the car off and ordered a new volatage regulator got home and installed it. Started the car, checked the voltage..14.2v ok good to go. After getting the wheels and tires on I decided to drive it to work last week. As soon as I left my neighborhood the ALT light came on but I drove it 20 miles to work anyway. I checked the voltage at my shop and it fluctuated 15 - 15.5. When I turned the lights on It pegged the guage over 17v. So i chucked it up to a bad voltage regulator again. Called the parts store and had them swap it out with a another one. Installed that one and started engine and measured 14.2v ok good to go i got a bad voltage regulator out of the box. So I painted my car this weekend and needed to move it around I noticed the ALT light was on again...damn. Checked the voltage and it reads 15.3v and when I turn lights on or hit the brakes it goes to 17.3v As I was messing with the regulator making sure I had good grounds one wire going from the VR connector to a condensor looking thing bolted to the VR. It had a resistor or fusible link possibly in the wire but it snapped and broke, all kinds of green corrosion inside. I tried to replicate the wire and plice it but no change so I disconnected my "rig it up" and now I'm not sure where to turn. Can I buy a new VR condesor looking thing and splice it back into the harness? Should I get this VR swapped out again? Could my alternator put out to much power to kill the VR? I know the alt looks old and rought but my theory was that it's the alt's job to charge and VR's job to regulate - but could the ALT still be bad?

Take a look at this picture, the round condensor/resistor?? rusty round cylinder bolted to the VR, what is it and can I buy a new one? Is it needed the voltage readings didnt change regardless if it was connected or not.
That's the radio condenser. It is basically a capacitor for the radio to try and stabilize the voltage a little more. Even if you have a good one today those things are in bad shape just from age.

It would not cause any problems having it disconnected. They only added it for am/fm radios the am radios didnt need it.

The voltage fluctuates alot even with a good regulator. But maybe your battery isn't good? How old is it? What I noticed was when my car was warming up the voltage was high, as it stabilized it would be normal or slightly below.

When the car sits do you have a battery charger hooked up to keep the battery charged?
Well thats nice to know. The battery is not that old maybe 2 1/2 years old. Its strange the engine was cold when I swapped out the replacement unit. It seemed to settle out right nice, however I do disconnect my battery when I'm done with the car, maybe leaving a lead loose accidentally cause voltage fluctuations.
Ever seen the scene in Office Space where they take the fax machine out to an empty field and beat it with a baseball bat? That's what I did with 2 or maybe 3 voltage regulators. I'm not even sure if they were the problem in hindsight, but well, they probably were.


Although they aren't cheap, I recommend converting to a 1-wire externally regulated alternator. It's the first thing I did when I got my 1970 barn-find a 2 months ago. I know you are on a tight budget with your car, but the increased capacity, brighter lights and lack of saying...what if on VRs is peace of mind enough.

When I move up to VA and we link up I'll give you all my alternator parts (if I have any left). I remember cleaning out stuff a few weeks ago and I saw a voltage regulator...I got chills as I tossed it out. I hate those things.


-Former 70 & 72 Mustang Owner.
-69 Torino GT, Formal Roof, 351W, Edelbrock 600 cfm, Edelbrock 351W Performer RPM intake, headers, AOD trans, dual flowmasters w/H pipe, Pertronix II Billet, 3.5 TRACLOC g/r, 15" Magnum 500s, 100A alt, aluminum radiator, electric fan, Pro-car seats, mini-starter...owned since Dec 13.
-70 Mach 1, 351W, Edelbrock E-Street EFI, VHX instrument cluster, Hooker headers, dual flowmasters, Pertronix II, 15" Magnum 500s, 150A alt, aluminum radiator, dual electric fans, Pro-car seats, mini-starter
If you have corrosion on the radio suppression capacitor, you probably have corrosion on other wires going to the voltage regulator. If that's the case, your VR won't work as it is designed to, and is probably the reason for your overcharging the battery.

Let me check your shorts!

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I had an over charge issue years ago which resulted from not having proper grounding to the body from the battery. Make sure you have a clean ground connection to the body (usually at the apron via the lower voltage regulator bolt) as well as to the engine block.
Where are you grounding? On my 72 the neg battery cable has a tab that is attached to bottom bolt on the VR. I do not see that you have one there, though i seen other cars that do not have the tab on their neg battery cable. So where is your ground to the firewall? you might consider getting the battery cable with the ground tab. Even with the correct grounds we get corrosion and need to clean the ground contact from time to time depending where you live. Ever looked in a VR? it is awsome! a couple rusty screws, a corroded spring and some ceramic posts i think. Great mechanical engineering for the time but you can do better. BTW i tossed more than a couple PEP boys replacements in the past. The real Ford were the only one that ever worked well. Then i bought a transistorized one with concours looking cover. Havent had a problem with THAT part of the system since. I am willing to bet you have a missing ground problem. That will cause all kinds of strange problems and kill parts like VR's and coils. also a new harness with the correct plug to the VR is around 40 bucks.
I have noticed that my negative bat cable only goes to the engine block and never to the chassis. There is a lead on my neg battery cable at the post that you can crimp a wire to, so maybe I will add a ground wire to the VR and try that. Should help with my lights going bright and dim at random as well.

I will probably get a ford replacement one as well. I don't want to destroy a $50 part that I may or may not be able to swap out like the $25 one from the parts store as my shop has a commercial account with them and I get to reap their benifits.
the neg battery cable is suppose to go from the battery to the same spot as the radio noise supressor capacitor on the VR then down to the engine block there is a bolt on the front of the block for the connection.
that gives you a solid body ground.

pull the VR and Sand the contact areas clean, use some dielectric grease on the contact points, then hook up the battery cable the connection point for the VR then sandwhich the ground connections onto the VR and bolt everything together tight.
make sure the bolt is clean also and put some dielectric grease on it as well.
72H, that is what i was describing above. I see more and more part distributors that see parts that new owners of classic cars will install, like a NEG battery cable without the ground tab, and the result is huge elect/ignition failure due to the incorrect part. Sucks for the customer, the parts distributor doesnt care because we come back to buy replacement parts. Kinda pissing me off.
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