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Over charging alternator

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Old 12-24-2013, 06:12 PM
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Over charging alternator

Added 75 f250 with 390 auto to my dentside collection. There's a new alternator, solenoid, interstate battery and belts. It's charging at max output, the indicator gauge is pegged all the way to the right at full charge. The lights are brand new bright even though their old. Put in nearly dead 850 amp battery, charged it in 15 minutes to the point that it spins the motor like the plugs are out. I checked the part # and it's correct for the year make and model. Worried that I'm going to over charge battery, I have 1 more dead battery left to put in it. HELP
 
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Old 12-24-2013, 06:38 PM
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Sounds like you may have a bad voltage regulator .
 
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Old 12-24-2013, 06:45 PM
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Do you have a multi-meter to check the actual voltage it is charging at?

The gauges tend to be "a little" inacurate...
 
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Old 12-24-2013, 06:51 PM
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Originally Posted by privateer, eh
...The lights are brand new...even though their old.
Are they brand new or old?

Either way, that's just an aside.

This sounds like a good reason to put a 3G alternator into your vehicle!
 
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Old 12-24-2013, 07:17 PM
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I'll look at the regulator in the morn to see if it's been replaced JWC 3, in the meantime I'll check the parts catalogue to see if the voltage regulator in my 75 Scab 250 with 460 auto is the same. The lights are old and I can't afford a 3g alternator psychlopath. Haven't seen my multi meter in months, probably got borrowed by buddy with train hobby, lots missing from my electrical box, starting to hate trains there AK Ford Guy. Other than the charging problem this truck is a blast. Don't normally like loud trucks but I get a Dukes of Hazzard rush when I hit the loud pedal. Thank you for your fast responses.
 
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Old 12-29-2013, 10:42 PM
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Marched buddy Dwight down to Quality tools and made him buy me a new multi tester as he left mine in friggin Salmon Arm, B.C. Got real pissy when it cost him $50 to be stupid and leave my tools in another province, don't think he'll be borrowing again. Did the neg cable off test to make sure I had no shorts. Engine off test showed 12.45+-.05. volts. Engine running test showed 13.5 +- .5 volts so that part is okay. Going to think my gauge has gone shot, I've got the gauge from a 89, 78 and another 75 if it needs replacement. I'm hoping that's my problem as theres nothing in my Haynes that says otherwise. Thank you AKford
Blew my hood light with the alarm so now I'm putting in a deadman switch direct to the battery, have inline fuse, just need to get the height on the hood right. Hooked up a washer fluid reservoir, have 4 sprayers to rig up, putting in a mixture of washer fluid and india ink.
 
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Old 09-04-2014, 12:13 AM
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FMC400 I think I need you

Originally Posted by privateer, eh
Added 75 f250 with 390 auto to my dentside collection. There's a new alternator, solenoid, interstate battery and belts. It's charging at max output, the indicator gauge is pegged all the way to the right at full charge. The lights are brand new bright even though their old. Put in nearly dead 850 amp battery, charged it in 15 minutes to the point that it spins the motor like the plugs are out. I checked the part # and it's correct for the year make and model. Worried that I'm going to over charge battery, I have 1 more dead battery left to put in it. HELP
I'm still having an overcharging problem, up until now I havent used this truck to often but its about to go into full service. A month ago I drove it about 30 miles to look at and buy another truck. I opened the hood and we heard a hiss coming from the battery. We put a voltage tester on battery and it read 14.7 volts with the motor off. I let truck cool off for an hour, took off the wiper blades. being a natural born genius I drove it home with the wipers, lights, heater motor on high, plus I had the flashers on, radio on and rode the horn. Luckily I made it home in one piece. The last time I messed with the truck I changed the voltage regulator with the one in my 75 Scab 460 c6 as the part # was the same in the Autovalue catalogue.

I have 2 more voltage regulators with condensor available before I need to buy any new ones. I was going to turn on the headlights in order to drain the battery before removing it. I have lots of safety and splash safe equipment available. The battery is an 8 month old Interstate with 850 cca's, is battery storage going to be a problem and will it be safe to remove.

If replacing the voltage regulator doesnt work should I follow my Chilton manual and adjust the voltage regulator or is that a bad wives tale that the book is promoting in order to give fools shock therapy. If everthing is new except for the voltage regulator what else could be wrong? The truck has sat for a month without being started.
 
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Old 09-04-2014, 07:48 AM
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Go ahead and safely (with goggles) measure the battery voltage one more time while it's running, with the assumption that it will be overcharging. Connect a jumper wire from one of the regulator mounting bolts to clean, unpainted metal on the engine (ground) and see if the number climbs back down. If not, replace the regulator. It's the most likely culprit.

Most modern regulators are electronic and non-adjustable. If you ever encounter the need to adjust an original electromechanical regulator, it should just be replaced with an electronic version.
 
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