1965 Dim Alt Light

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Jun 13, 2009 | 08:09 PM

F250GH

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Tuned

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1965 Dim Alt Light

What are the conditions that cause the alternator light to burn dimly? New Motorcraft alternator, Napa electronic voltage regulator, correctly charging at 14 volts at idle.

Jun 14, 2009 | 05:54 AM

NumberDummy

Ford Parts Specialist

Joined: Nov 2006

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From: Simi Valley, CA

Quote:

Originally Posted by F250GH

What are the conditions that cause the alternator light to burn dimly? New Motorcraft alternator, Napa electronic voltage regulator, correctly charging at 14 volts at idle.

The wrong wattage bulb, or a bulb that is dying from old age.

The lens in front of the bulb might need a little cleaning.

Jun 14, 2009 | 06:49 AM

F250GH

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Tuned

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Bulb illuminates brightly with the key on, the problem is the dim glow while at idle.

Jun 14, 2009 | 06:56 AM

NumberDummy

Ford Parts Specialist

Joined: Nov 2006

Posts: 88,826

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From: Simi Valley, CA

Quote:

Originally Posted by F250GH

Bulb illuminates brightly with the key on, the problem is the dim glow while at idle.

That's common, they all do that...since they were branny new. It's also common for the light to flicker.

Jun 14, 2009 | 06:56 AM

banjopicker66

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Joined: Apr 2002

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From: Coal country

If your idle speed is not set too low, then I would bet you have a bad ground somewhere. The most frequent culprits in my experience are: Battery to wiring harness Battery to body sheet metal Battery to alternator and regulator Engine block to body Engine block to wiring harness. Core support to wiring harness Wiring harness to inner fenders Wiring harness to cab