[Jim69Mustang]

I have upgraded my Stang to a 140 amp single wire alternator. I have also installed two batteries. I cannot keep the batteries charged. Initially when I start the car the alternator provides about 13.8 volts. In about two minutes it drops to about 12 volts. THIS IS A STEADY DECLINE NOT LIKE SOMETHING IS KICKING IN. I get about three starts out of the two batteries. After that I have to put a charger on each. Any ideas as to my problem?

WOULD IT BE BETTER IF I TRIED A 16 VOLT ALTERNATOR?

NOTE: ABOVE CAPITALIZED SENTENCES ARE AN UPDATE.

[ April 24, 2003: Message edited by: Jim69Mustang ]</p>

[4 Jaw Chuck]

Bad regulator?

[Zombie]

anything kick on/startup after two minutes , like an electric rad fan ?

is it a slow decline to 12 volts or a jump down ?

[98rocket]

jim, are both batteries new? if one of the batteries is low, it will drain the other battery until the two are equal. if one battery is bad (unable to hold a charge), it will constantly pull from the good battery until they are both dead.

after charging, try connecting one of the batteries up separatly. if that battery can start the car and continue to hold a charge on its own, the other battery is bad. make sure to test both batteries this way. if neither battery works on its own, the problem is another component: the regulator or maybe even the new alternator.

[we93]

hey, some 1 wire alternators need to see atleast 2500 to 3000 rpm before they will charge on initial start up....

[48Man]

Go to Auto Zone and have them do a free Batt and alt test. Also go to this site and check out the 1 wire alt vs the 3 wire alt. Also, you might consider a battery isolator as part of you install.

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[48Man]

Forgot to post the site

http://www.madelectrical.com/

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