Voltage Reading Less Than Specified!!
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Voltage Reading Less Than Specified!!
My voltage reading on my bat is 12Volts. When i start the engine it slowly goes to 13.4 {should be between 14-15} When i turn on my lights on it lowers but does not come back up. I have replaced the alt. but it did not raise up the voltage!!! Not sure what eles to ck.
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The output of an alternator is proportional to its RPM. At the relatively slow idle speed of these trucks I have found that the output of the stock alternator is not enough to run the ignition, PCM, lights, and A/C blower all at the same time.
Cleaning up grounds and alternator and battery connections will make this better, but there fundamentally isn't enough juice to go around.
As long as the voltage doesn't drop below about 11.5 volts, and as long as the system reaches full voltage (14 to 15 volts) by 1400 RPM or so, charging the battery won't be a problem and there won't be an operational issue with the voltage drop at lower speeds.
My old and high mileage 1991 farm truck can manage to operate the lights OR the blower at idle without a significant drop, but cannot operate both at the same time without the voltage dropping down.
Later model cars, with electric fans and fancy sound systems have incorporated alternators with more grunt at low speeds.
Cleaning up grounds and alternator and battery connections will make this better, but there fundamentally isn't enough juice to go around.
As long as the voltage doesn't drop below about 11.5 volts, and as long as the system reaches full voltage (14 to 15 volts) by 1400 RPM or so, charging the battery won't be a problem and there won't be an operational issue with the voltage drop at lower speeds.
My old and high mileage 1991 farm truck can manage to operate the lights OR the blower at idle without a significant drop, but cannot operate both at the same time without the voltage dropping down.
Later model cars, with electric fans and fancy sound systems have incorporated alternators with more grunt at low speeds.
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Joined: Nov 2004
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????
Thanks for the Info. Recently Had someone put in A CD radio in my truck. THe Power will now come on but 0 sound. BUT When I changed the battery out and started her up the Radio Came On and played until I shut it Off and attempted starting it again. she wouldn't play. Is it A speaker wire Bad ground?
Could they have screwed something Up? Should I just pull radio fuse or Pull it and trace all there connection?
Could they have screwed something Up? Should I just pull radio fuse or Pull it and trace all there connection?
Originally Posted by fefarms
The output of an alternator is proportional to its RPM. At the relatively slow idle speed of these trucks I have found that the output of the stock alternator is not enough to run the ignition, PCM, lights, and A/C blower all at the same time.
Cleaning up grounds and alternator and battery connections will make this better, but there fundamentally isn't enough juice to go around.
As long as the voltage doesn't drop below about 11.5 volts, and as long as the system reaches full voltage (14 to 15 volts) by 1400 RPM or so, charging the battery won't be a problem and there won't be an operational issue with the voltage drop at lower speeds.
My old and high mileage 1991 farm truck can manage to operate the lights OR the blower at idle without a significant drop, but cannot operate both at the same time without the voltage dropping down.
Later model cars, with electric fans and fancy sound systems have incorporated alternators with more grunt at low speeds.
Cleaning up grounds and alternator and battery connections will make this better, but there fundamentally isn't enough juice to go around.
As long as the voltage doesn't drop below about 11.5 volts, and as long as the system reaches full voltage (14 to 15 volts) by 1400 RPM or so, charging the battery won't be a problem and there won't be an operational issue with the voltage drop at lower speeds.
My old and high mileage 1991 farm truck can manage to operate the lights OR the blower at idle without a significant drop, but cannot operate both at the same time without the voltage dropping down.
Later model cars, with electric fans and fancy sound systems have incorporated alternators with more grunt at low speeds.
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