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Thank to all who responded to my seatbelt questions (rear belts, 66 coupe). Yes the holes were factory drilled and stiffening plates were welded around the holes. The install was pretty easy after I had an idea where to look. The outboard holes were on the rear facing panel, not the side panel like the vert, but pretty close. The inboard holes were being used for the exhaust hangers.

When I went to start the car to make a parts run I got the solenoid "click of death" and found the battery voltage to be below 11 volts, oh oh. I jumped the car and checked it while running, same voltage. After I installed a rebuilt alternator the run voltage went up to about 13 volts. I had left the battery on a charger overnight so the battery had a pretty good charge, but I wanted to know what the normal running voltage of the charging system is. Will 13 volts keep the battery charged?

Thanks in advance.
 

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Try a Motorcraft electronic voltage regulator. Allows the alternator to "keep up" at idle plus no points to stick and boil the battery over.

Check the voltage without the car running, then test it with it running... Should be 13.5-14 volts. You can increase the charging rate by removing the cover to the voltage regulator and bending the "tang" that holds the spring so as to allow more tension on the spring...Just don't go too far!
 

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bear in mind the wiring in the car may be old and have small amounts of resistance here and there....you have to be slightly subjective with these old machines!
 

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13v is not enough to maintain a fully charged battery. The alternator should be at 14.7 volts on a standard day (75 degrees) at 1000 rpm and should handle all accessories on without dropping. If you're not getting this, the regulator needs adjustment (old type) or replaced (new solid state type). If you're not getting this with a good regulator, chances are you have a open diode in the alternator or have a lot of aftermarket accessories exceeding the alternators capability.
 
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