Still pulsing electrical

Charging, starting, lighting, gauges, HVAC

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Truckee250club
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Still pulsing electrical

Post by Truckee250club »

Brand new battery, voltage regulator, alternator, and properly adjusted belt, all lights pulse above idle, seems to get better the more power I draw. Eg: pulses slower when I turn the lights on, again with the radio, once more with the heater, and again with the aftermarket hid off road lights. I have yet to solve it. Any ideas?
71' F-250 4x4 390 BW-T18
fmartin_gila1
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Re: Still pulsing electrical

Post by fmartin_gila1 »

I would suspect the new VR is bad. The Regulator is supposed to control the Alternator to come up to specified Voltage and then cut back just enough to maintain that Voltage and to adjust the output of the Alternator to maintain that Voltage under varying loads depending on what is turned on.

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sargentrs
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Re: Still pulsing electrical

Post by sargentrs »

Did it do that before the off road lights?
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Truckee250club
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Re: Still pulsing electrical

Post by Truckee250club »

It did do it before the off road lights. I'll try a new voltage regulator.
71' F-250 4x4 390 BW-T18
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HIO Silver
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Re: Still pulsing electrical

Post by HIO Silver »

I think it's a combo of a lower power alternator and marginal VR.. the latter actually has amperage ratings so ya might have a mismatch. Plus the HID headlights aren't helping matters.
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Mach428
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Re: Still pulsing electrical

Post by Mach428 »

I had this same problem with my Mustang. It turned out to be the wiring harness from the alternator to the VR had a bad ground. You may want to check that and ensure that the harness is in good shape AND that the ground wire from the harness is connected to the block.
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