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Discussion Starter #1
I'm not sure if this is a problem or not. The charging system on my 69 Mach seems to be charging too much. Measured across the battery terminals with the engine running I get 15.2 to 15.7 volts. When I first brought the car home last fall it had acid coming out of the caps on a repro Autolite battery, chaulked it up to a junk re-pop. This is the readings I'm getting now with a new "sealed" battery installed. The regulator is new and the alternator checked in spec at NAPA. None of my manuals list normal voltages, are these too high or am I being too cautious. Thanks for any advice.

68 restomod coupe
69 Mach1
67 coupe Son's
 
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Discussion Starter #2
Bad regulator. should be 14.2-14.7 volts at apprx 1000rpm

Greg B
 
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That's what I thought, but this is the second new regulator I've put on it, same results. All grounds look good, am I missing something?

68 restomod coupe
69 Mach1
67 coupe Son's
 

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Buzz out all wiring in charging system. One of the wires from the alt to voltage reg may be open or shorted.

Good luck...



Steve Leslie, 65 coupe in restoration. 302, toploader, A/C, disc brakes, bench seat

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I can't remember if it was a Ford or not but I had a similar problem on one of my cars a while back and discovered that the regulator could be adjusted down.
 

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Mechanical or electronic regulator? I stopped using mechanicals for that very reason when I still ran Harleys. They used the same type as the old Fords on the old Knucks and Shovels I used to play with. If they can be adjusted the vibration will knock them out of spec. I replace the electronic regulator whenever I replace the alternator. I run at 14.3 volts when above idle. I think that mght be why you are boiling your battery. Another poster suggested buzzing the wires and I think that is a good idea as well. You can use an ohmmeter to be sure that all of the wires are okay. If you have never replaced the wires or connectors be ready to replace some of the connectors. The copper wire is sensivite to vibratition and breaks at the connectors pretty easily. If you have to crimp on a new connector, be sure that the copper wire is very clean so you get a good connection between the crimped connector and the wire. Sandpaper or gentle scraping will expose fresh copper.
 
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Discussion Starter #7
Overvoltage from the alternator results in battery water/acid boiling off just as you described. A possibility is the previous owner did some jackwiring to get the alternator to work. The reason the alternator is putting out so much voltage is the rotating field is being overexcited, perhaps by steady battery voltage rather than regulated voltage from the VR. Look for tell tale signs of respliced wires. Glad to tell you how to check your wiring but need to know whether you have a dash light or a dash mounted ammeter since the wiring is different although the VR is the same. Promise I won't talk in terms of wire colors. Come back with a new post if you want to give it a shot.

Mustang Lovers ---- A Box-O-Choclates !!!
 

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take your alt and reg to shop (AutoZone, Advance, etc.) and have them checked as a pair- usually no charge or maybe $5 or so. then you know that is not your problem and you do not have to rip up wiring looking for bbad grnds
 
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