Voltage High
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Cargo Master
Joined: Sep 2004
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Voltage High
I have a 1992 F150 2wd with 300 I6 and 5 speed. I replaced the voltage regulator. With the old one in there, the voltage would intermittently flutter around center on the dash voltmeter. Sometimes it would flutter, and sometimes not. When not fluttering, all was good. When fluttering, I would sometimes have problems with electric things turning off and on. Examples of this are the radio turns off for a second if I hit the brake or turn on the turn signal. Sometimes if I hit the brake pedal the engine will cycle on/off. There was no pattern to any of it. It was completely intermittent. I put on a new voltage regulator and I have the same intermittent problems with things cycling off/on. The difference is that when the truck is in this bad state, the voltage is almost pegged at the high end (18 volts). It doesn't flutter anymore, it just reads high. On some evenings if I have the radio, heater motor, and headlights on, and I turn up the volume on the radio, the voltage will drop way down and the heater motor slows, the headlights dim, and the engine almost dies. If I turn down the volume, everything picks back up.
Anyone have any ideas? I'm completely stumped. Why would a voltage regulator not regulate?
Anyone have any ideas? I'm completely stumped. Why would a voltage regulator not regulate?
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From: Virginia
The seperate type regulators get their voltage info from the yellow wire on the "A" terminal of the regulator. I would check the "A" regulator plug connection, and the "A" wire and the other end of the "A" wire where it usually hooks to the large battery connection on the starter relay.
Of course the regulator references the voltage it gets from the "A" connection to the ground connection on the housing of the reg, so if the ground to the reg is not very good, it can also send bad info to the alternator, making it over or under charge.
Of course the regulator references the voltage it gets from the "A" connection to the ground connection on the housing of the reg, so if the ground to the reg is not very good, it can also send bad info to the alternator, making it over or under charge.
Last edited by Franklin2; Sep 12, 2007 at 11:04 AM.
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From: Virginia
Sorry, I thought you may have had the older system where the reg mounts on the inner fender or the radiator support. I believe this is a diagram of your system, and the yellow/white wire is the one you need to look at.
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Cargo Master
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Thanks for the pic.
On the bottom of that pic is what looks to me like a ground for the alternator. Is this true? If so, how is the alternator grounded? Is it grounded just by being mounted to the block?
On the bottom of that pic is what looks to me like a ground for the alternator. Is this true? If so, how is the alternator grounded? Is it grounded just by being mounted to the block?
Last edited by qman; Sep 13, 2007 at 10:36 AM.
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