The Ford Barn

tsanborn · 11-07-2025, 06:32 PM

I've replaced the generator in my '56 Country Sedan with an alternator and rewired the car with a Painless harness. Everything is working except I'm not getting the amp light to illuminate when the ignition is on but not running. There is power passing through the bulb to the white exciter wire that plugs into the alternator. It is a GM style 10SI with a red and a white wire plug. If I pull the plug out and short it to ground, it illuminates. Any thoughts? I've asked Painless and they were not a lot of help.

justold · 11-08-2025, 06:10 AM

If it is a one wire alternator that function normally doesn't work .

40cpe · 11-08-2025, 11:14 AM

https://www.youtube.com/watch?v=qNRp9SkpNi0

rotorwrench · 11-13-2025, 12:48 PM

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The old generator lights were turned off by the cut out in the voltage regulator back in 1956. The modern set up for alternators is different since it's controlled by the alternator VR circuit but it can be made to work. There should be info on this site and on U-tube about these modifications.

11-07-2025, 06:32 PM	#1
tsanborn Member Join Date: Nov 2020 Posts: 51	amp dashboard light not illuminating I've replaced the generator in my '56 Country Sedan with an alternator and rewired the car with a Painless harness. Everything is working except I'm not getting the amp light to illuminate when the ignition is on but not running. There is power passing through the bulb to the white exciter wire that plugs into the alternator. It is a GM style 10SI with a red and a white wire plug. If I pull the plug out and short it to ground, it illuminates. Any thoughts? I've asked Painless and they were not a lot of help.

11-08-2025, 06:10 AM	#2
justold Member Join Date: Jan 2013 Posts: 60	Re: amp dashboard light not illuminating If it is a one wire alternator that function normally doesn't work .

11-08-2025, 11:14 AM	#3
40cpe Senior Member Join Date: May 2010 Location: Star, MS Posts: 4,161	Re: amp dashboard light not illuminating https://www.youtube.com/watch?v=qNRp9SkpNi0

11-13-2025, 12:48 PM	#4
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 18,006	Re: amp dashboard light not illuminating Sponsored Links (Register now to hide all advertisements) The old generator lights were turned off by the cut out in the voltage regulator back in 1956. The modern set up for alternators is different since it's controlled by the alternator VR circuit but it can be made to work. There should be info on this site and on U-tube about these modifications.