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Discussion Starter #1
If I measure the voltage at the alternator terminal I should get at least 14.5 volts right? I have only 12.5V at the battery and alt terminal. I am thinking I have to replace the alt and Voltage reg.
Any suggestions? Opinions?
Thanks in advance...
 

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At what speed? Your idle speed may be too low.

Next, try momentarily touching 12 volts directly to the "field" terminal of the altinator. If nothing happens, dead alt. It there's a rise in voltage, dead regulator. You could also put a volt meter to the field to see if you have power there as well. Up to you.
 

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Discussion Starter #3
I checked at idle and then revved it pretty good without any fluxuation in the reading. Oh, I forgot to mention '71 302 with underdrive pulleys.
 

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Discussion Starter #4
Update:
I did check the field-no voltage.
After I went out at lunch and bought a new alt and VR I noticed that a bullet plug had come off going to the Voltage Reg. The Green one I think.
Well now It looks like I might have a spare VR and Alt, oh well at least I can use them on one of my other cars if needed.
 
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All Mustangers need spare parts...My trunk is full of new parts. You never know..... :) :)
 

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Tell me about it. Went to start the car today. No spark. After some basic diagnostics, popped the dist cap. Low and behold my points (installed in June) fell apart. Literally. The post that holds the primary and condensor wires (as well as the spring) pulled through the plastic that was "holding" it in place and grounded against the dizzy housing.

Luckily had the old set I removed in a box in the trunk. Made it to the parts store and got new ones. Probably explains why it ran so rough the other day...

Maybe it's a sign to go ahead with the MSD rig I've been looking at!

Frank
 

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if your engine was running that is not enough - should be between 13.5 and 14.5 Vs and you can check it at battery terminals unless you suspect broken wire 38/37 to alt from batttery + term. could be loose fan belt (usually volts will go up when you increase RPM if loose belt), VR connection and other causes. usully AutoZone does free check in car. PM me if questions.
 
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