Charging Problems '92 F150
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Charging Problems '92 F150
Hello Everyone:
I have a good alternator (rebuilt and tested, small pulley as well), good battery (load tested), wires all appear to be good and fan belt has been replaced but when the truck is at idle (approx 600 rpm) it will not charge. When the rpm comes up to about 800 or so the alternator kicks in and charges normally.
One auto electric guy tells me that this was a problem with early '90's Fords. Is my idle set too low? Or is there some other potential cause?
Thanks for any help anyone can provide.....
Brian Shury
I have a good alternator (rebuilt and tested, small pulley as well), good battery (load tested), wires all appear to be good and fan belt has been replaced but when the truck is at idle (approx 600 rpm) it will not charge. When the rpm comes up to about 800 or so the alternator kicks in and charges normally.
One auto electric guy tells me that this was a problem with early '90's Fords. Is my idle set too low? Or is there some other potential cause?
Thanks for any help anyone can provide.....
Brian Shury
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Joined: Mar 2003
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From: Bartlett, TN
When you say that it's not charging, exactly what do you mean. If you put a DVOM on the battery, at Idle, what is the reading? 12V, 14V, or < 12V. If less than 12V at idle, check the two 8ga wires on the larger alternator plug. These wires are notorious for burning out, causing erratic charging.
If the alternator is outputting 12V at idle, have someone load test the alt while in the vehicle, and record the amperage output at idle, and at 2000 rpm. You should expect the readings at idle to be lower, with full amperage output at 2K.
Sean
If the alternator is outputting 12V at idle, have someone load test the alt while in the vehicle, and record the amperage output at idle, and at 2000 rpm. You should expect the readings at idle to be lower, with full amperage output at 2K.
Sean
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At idle the voltage is about 14.4 volts with no electrics on. When I turn on the lights and radio the volts drop to approximately 13. When the fan is turned on as well the voltage drops to 12.4 and continues to decline if all of the electrics are on. When I kick the rpm up to about 800 or more the alternator seems to pick up the load again and reads approximately 14.4 volts.......
I am tempted to try another alternator.
Brian
I am tempted to try another alternator.
Brian
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