Very fluctuating Volt gauge
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Very fluctuating Volt gauge
My 96 F-250 5.0l has developed a weird issue. The volt meter goes from N to M on the Normal reading at the drop of a hat and vise versa. It did it while towing and then just stuck at N. Took the alt to a local very rep. starter/alt shop that I deal with and they said she was bad. Battery was fine and was recharged before the new alt went on. Drove fine then it returned. Dropped it almost exclusively up hills while towing. Thinking it was a short in the trailer I unhooked the trailer brakes and lights. Still is doing it now on occation without a trailer attached. Any ideas? Terminals on the battery look just duckie as do the terminals on the starter. Connecter for the alternator was in nice shape when I replaced it 3 months ago.
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Joined: Jan 2001
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From: Virginia
Check the belt and the belt tension/tensioner. Check the small ground straps going from the engine block to the firewall.
Also look for signs of other problems like noise on the radio, the fan blower slowing down or the lights going dim, etc. Just to verify that we can believe the gauge, and the voltage really is going up and down.
Get someone to watch the engine while you rev it up and down, and see if a motor mount may be bad or loose, possibly pulling on the wiring. A Ford motor mount going bad is rare, but it would explain the hill thing while towing.
Also look for signs of other problems like noise on the radio, the fan blower slowing down or the lights going dim, etc. Just to verify that we can believe the gauge, and the voltage really is going up and down.
Get someone to watch the engine while you rev it up and down, and see if a motor mount may be bad or loose, possibly pulling on the wiring. A Ford motor mount going bad is rare, but it would explain the hill thing while towing.
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Everything seems to be clean and tight as far as grounding straps and the mm. Today I drove it again about 10 miles. When about home the battery light came on. Volt meter is reading 14.4 volts with the engine running. Battery is showing 13.0-13.2 when not running.
Ideas? 14.4 seems a little high but not overly high right?
Ideas? 14.4 seems a little high but not overly high right?
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Joined: Jan 2001
Posts: 57,027
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From: Virginia
14.4 is right on the money. Interesting the battery light came on. I know they rebuilt the alternator, but do you think it could still have a problem? It could be intermittent and they didn't see it when they worked on it.
