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I’ve recently started having a low voltage reading at night while at idle with the lights on. I have an electric fan, retro sound stereo and the Dakota digital dash. If I turn the heater on with the fan going, lights on, stopped at idle my volt reading drops to 10.9 and starts blinking. Jumps right back up while driving. I installed new battery, new belts, and a new stock alternator from autozone. Also put in a new solid state voltage regulator. Question is, would getting a higher amp alternator like a 100 amp boost up the volts at idle? Or running a smaller pulley on the alternator? If so do you guys know where I can get a higher amp 3 wire alternator or smaller V pulley for the alternator.
 

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Since you are already using Dakota Digital, I would upgrade to a 150amp one-wire internally regulated alternator. Simple to install, and you get rid of the external regulator and wiring. I just did this upgrade and it works like a champ. I also run Dakota Digital dash, electric fan, fuel injection and a small stereo. At idle, I am between 13.8- 14.0 volts.

Tim
 

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It's probably not your alternator, but your Voltage Regulator making you experience "Voltage drops". If you are still going with an OEM Points type unit...That's why. You need a "Solid State" Motorcraft unit...like below...

https://www.npdlink.com/product/voltage-regulator-alternator-electronic-replacement-from-the-oe/100810?backurl=search/products?search_terms=voltage%2Bregulator&top_parent=200001&year=

or this one..

https://www.rockauto.com/en/parts/motorcraft,GR540B,voltage+regulator,4884


They are the way to go.... Try one first before you start swapping out alternators..

:eek:)

Tony K.
 

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I would switch to a more modern Ford 3G alternator, small case at 130 amps should fit the bill. Would stick with a "3 wire" (output, exciter, ground) which makes for an easy hook up while still retaining your original alternator warning lamp, if used.
 

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Another vote for 1 wire here. I went that route and never looked back. The most important part is to size the charge wire correctly. I found a 6awg "lawnmower power wire" at the parts store. It has eyes on both ends.
 

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I would switch to a more modern Ford 3G alternator, small case at 130 amps should fit the bill. Would stick with a "3 wire" (output, exciter, ground) which makes for an easy hook up while still retaining your original alternator warning lamp, if used.
Gotta agree with Woodchuck .... mostly.
One thing a 3g does well, is sensing voltage needs at idle. it does this best when the sense wire is run to the solenoid, instead of looping to the output. I saw a .5 volt difference.
So I guess a 4 wire hookup. I needed a ground also, probably cos I ceramic coated the case and brackets.
 
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