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any body have this problem,truck was over charging about 18 volts with fully charged batts.figured it was the regulator , changed it and figured it was aok,but when popped the hood to check oil notice batt acid around caps on both batts.checked the voltage and found about 16 about half throttle.should i just swap the alt.thats probably couple hundred bucks or try another reg?
Last edited by rancherman84; Jan 7, 2004 at 08:36 PM.
Try connecting a jumper from the regulator base to the alt frame or bracket,if the over charge disappears check the ground connections on alt,reg,and from engine to dash panel and to batt. If it is still overcharging disconnect the plug from the voltage reg,start engine, run up to 1500rpm,volts shouldnt go up more than 2.5 volts above base voltage.If its still over charging check for a short between circuits A and F in the reg wiring harness.Hope this helps.BTW we are talking about an external regulator,right?
Nope, not very expensive if you have the alternator checked first- then you can buy with confidence :-)
Any parts store worth its fan belt has a set up to spin the alternator and see if it is charging or not...
And if you have double checked all your connections (especially if you have battery acid spilling- that will make bad connections quickly at the posts) and all the connections (terminals in weatherpacks in harness, at alternator etc) are good clean and tight, then simply have the parts store spin test the alternator.
You can also use a diagnostic tool to check the entire system, but by removing the alternator and having it spin tested seperately, that eliminates all the other possible variables.
And it is my personal experience that those internally regualted alternators are fussier then my wife. Arc a battery cable, jump start improperly, heck, they get all goofy.
In conclusion, if it is not a connection, then have the parts guys at NAPA, Big A, Parts America, O'Reileys etc etc spin test the alternator...
A shorted cell in the battery could cause the problem you are describing as well. a shorted cell shows low voltage in the battery so the regulator goes to full charge with no place for it to go.
Have a battery or parts store do a load test on the batteries....and make them test them one at a time. If they test with the wiring connected to both batteries, the good battery will mask the bad one.
you know now that you mention it i dont think i had this problem until i installed a new set of caseih batt i wiil load test them tomorrow and get back to you, thanks dave!
yep load tested batts today and the right one has 12 volts but 0 amps! the left one has about 10 volts (under load) and about 400 amps.both batts were replaced in dec. 03 had the parts man order me a set for monday.sure am glad the one is good it was -15f this morning but she fired right up! god i love my truck!
Glad to help, Everyone at the battery places think they can just put the tester on the without unhooking them. This lets the good battery mask the bad one. But it only fools the meter, not the alternator. Bad thing is it will fry the alternator if left long enough.
Just wait till you get both batteries working right, if you love it now, .....well you know what I mean.....I am chuckling now.