charging problem
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charging problem
hi all, its been a while. well. i am havin a problem with my 1988 f150 straight 6 truck not charging. started slowly discharging the battery i guess. i checked the volts with the engine off and read 12 and then with the engine on it dropped 11.24 and stayed their. its a efi engine so it started running really bad. then i was told that it was the alternator so i did one of my old tricks and started the engine and took off the neg cable and the engine died telling me that the alternator was not charging. checked the wires connections and all looked good. put another alternator and the same problem. now the battery is like dead so i'm charging it. battery read good too. CAN SOMEONE PLEASE HELP ME OUT HERE. I'M PULLING MY HAIR OUT HERE. PLEASEEEEEEE.
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Im pretty sure the truck will die no matter what if you take the ground off the battery but not possitive. Check battery voltage while vehicle is running. Should be at least 13.7, And im assuming you checked the fuses correct?
Last edited by tweaked250r; Mar 21, 2007 at 05:13 PM.
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hi, thanks for the reply, well, i had checked the battery voltage before i replaced the alternator. read 12 volts engine off. then with the engine on it dropped to 11.24 volts. i replaced the alternator and i had the same readings. i did not check fuses. i really don't know which ones to check.???
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well, i will be taking both alternators to auto zone tomorrow to have them checked.i just read on my haynes book, never start the engine with a battery charger connected, WHICH I DID. and always disconnect both battery leads before using a battery charger. WHICH I DIDN'T. did i mess something up???
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With the engine running, touch the back center of the alternator with a screwdriver/wrench-any thing magnetic,if there is magnetism ,alternator MOST likely ok.
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Originally Posted by john112deere
I doubt it.
I don't know these trucks at all, is the regulator integral to the alternator?
I don't know these trucks at all, is the regulator integral to the alternator?
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well, just got back from auto zone and both alternators failed. but the second one i had bought off a junk yard for $25 and i new i was taking a risk when i bought one off the junk yard. but i received my money back from the junk yard and now I'm getting one from the dealer for $50, heck of a deal. like they say. its good to have friends in the right places.lol. anyways. I'll be picking that one up this afternoon and I'll post the outcome. hopefully thats my problem.
i ain't rite
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From: Marlboro Mental Hospital.
never, never, never, never take the battery terminals off with the engine running. you can do all kind of damage, including but not limited to burning out the alternator, burning out the voltage regulator, burning out the computer, and setting the truck on fire.
and if that is not enough, hooking the battery up with the engine running could cause the battery to blow up in your face, causing acid burns, or worse, death if a piece of the battery casing enters your body.
and if that is not enough, hooking the battery up with the engine running could cause the battery to blow up in your face, causing acid burns, or worse, death if a piece of the battery casing enters your body.
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Originally Posted by tjc transport
never, never, never, never take the battery terminals off with the engine running. you can do all kind of damage, including but not limited to burning out the alternator, burning out the voltage regulator, burning out the computer, and setting the truck on fire.
and if that is not enough, hooking the battery up with the engine running could cause the battery to blow up in your face, causing acid burns, or worse, death if a piece of the battery casing enters your body.
and if that is not enough, hooking the battery up with the engine running could cause the battery to blow up in your face, causing acid burns, or worse, death if a piece of the battery casing enters your body.
i ain't rite
Joined: Mar 2005
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From: Marlboro Mental Hospital.
no problem.
once upon a time, back when alternators had an output of a whole 20 or 30 amps, this was an accepted method of testing if the alternator or generator was good or not.
but now with the high amperage alternators, you can very easily get a power spike of over 100 volts when you take the wires off the battery. with this spike, you can also see amperages in the 150+ areas. and when you let all this unregulated power out into the system, all kinds of nasty things happen. and then when you hook the battery back up with this power surge, you can get a big boom.
i have had 5 battery's blow up last year just from the spike you can get from energizing the alternator before starting on the mack trucks in work. hydrogen gas builds up in the battery, and a power surge sets it off. it is enough power to blow the battery box rite off the frame of the truck.
once upon a time, back when alternators had an output of a whole 20 or 30 amps, this was an accepted method of testing if the alternator or generator was good or not.
but now with the high amperage alternators, you can very easily get a power spike of over 100 volts when you take the wires off the battery. with this spike, you can also see amperages in the 150+ areas. and when you let all this unregulated power out into the system, all kinds of nasty things happen. and then when you hook the battery back up with this power surge, you can get a big boom.
i have had 5 battery's blow up last year just from the spike you can get from energizing the alternator before starting on the mack trucks in work. hydrogen gas builds up in the battery, and a power surge sets it off. it is enough power to blow the battery box rite off the frame of the truck.