voltage drops across the battery
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Junior Member
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voltage drops across the battery
I have a 93 f150 xlt, 302ci, at, awd
I have developed an issue in the charging system. When at idle and heavy electrical load, the voltage drops across the battery. Running Idle no-load is about 14.5v - 14.8v, Running at idle, full load starts at 14.5v and after a couple of minutes will drop to 12 to 12.5 volts. To the very point where windshield wipers get real slow, headlight go dim.
Ignition off- battery voltage is right at 12v. I have cleaned connections and battery posts.... I am at a loss in what to do next!!!
I have developed an issue in the charging system. When at idle and heavy electrical load, the voltage drops across the battery. Running Idle no-load is about 14.5v - 14.8v, Running at idle, full load starts at 14.5v and after a couple of minutes will drop to 12 to 12.5 volts. To the very point where windshield wipers get real slow, headlight go dim.
Ignition off- battery voltage is right at 12v. I have cleaned connections and battery posts.... I am at a loss in what to do next!!!
Senior Member
Joined: Oct 2002
Posts: 7,295
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From: St. Louis (Out in the woods)
Originally Posted by gspman
I have a 93 f150 xlt, 302ci, at, awd
I have developed an issue in the charging system. When at idle and heavy electrical load, the voltage drops across the battery. Running Idle no-load is about 14.5v - 14.8v, Running at idle, full load starts at 14.5v and after a couple of minutes will drop to 12 to 12.5 volts. To the very point where windshield wipers get real slow, headlight go dim.
Ignition off- battery voltage is right at 12v. I have cleaned connections and battery posts.... I am at a loss in what to do next!!!
I have developed an issue in the charging system. When at idle and heavy electrical load, the voltage drops across the battery. Running Idle no-load is about 14.5v - 14.8v, Running at idle, full load starts at 14.5v and after a couple of minutes will drop to 12 to 12.5 volts. To the very point where windshield wipers get real slow, headlight go dim.
Ignition off- battery voltage is right at 12v. I have cleaned connections and battery posts.... I am at a loss in what to do next!!!
Take it out and have it tested. Replace if necessary.
Steve
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voltage dropping
Sorry
I failed to mention that i just replaced the alternator 3 days ago???????
I am going to get my jumper cables out tmro and parallel the baterry cable under full electrical load. Maybe a bad cable
I failed to mention that i just replaced the alternator 3 days ago???????
I am going to get my jumper cables out tmro and parallel the baterry cable under full electrical load. Maybe a bad cable
Senior Member
Joined: Oct 2002
Posts: 7,295
Likes: 125
From: St. Louis (Out in the woods)
Just because the alternator is new doesn't mean it's good...... Measure its output at the alternator.
There is a 12 Ga fuse link between the output of the alternator and the battery. If it blows or goes tyo a high resistance, you won't get proper charging.
Steve
There is a 12 Ga fuse link between the output of the alternator and the battery. If it blows or goes tyo a high resistance, you won't get proper charging.
Steve
