Low charging volts
02-21-2007, 02:52 PM
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Low charging volts I have a massive problem that just arose the past few hours. My volts are down to 10! It is not charging but is staying pretty steady there as long as I am driving, while at idle I dip. I have a new belt on (replaced about a month ago) and just sprayed it down with electrical cleaner. I had it checked yesterday when it first happened but while I was driving it 'fixed' itself. I still had it tested and the volt reg and alt both tested out as good. Bad ground? I replaced this about 30K miles ago with a used one from the junkyard and cannot remember how I got it out without taking everything off. The little red wire is in it's connector still and under load the car runs everything just a little slower and with no dip in volts. i.e. wipers, windows. I have an Optima red top in the car and I really need this resolved since I am driving across country on MONDAY! What else could be the problem? I don't want to throw $120 at an alt when it could be used for the trip.
02-21-2007, 03:37 PM
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No, I was hoping it wouldn't be that since the battery is only 3 yrs old AND an Optima. I'm off to the parts store to go get it tested. Will return with answers.
02-21-2007, 05:16 PM
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Battery just tested good. It went in with about 500 CCA and came out with 843 CCA. I just put it back in the car started it and watched the volts drop right back down to where they were.
Plug on top? Is there an easier way to get it out other than dropping the whole alt? Also any tricks to getting the alt out quick and painless?
Plug on top? Is there an easier way to get it out other than dropping the whole alt? Also any tricks to getting the alt out quick and painless?
02-21-2007, 06:36 PM
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You need to know exactly what your voltage is; i.e. get a DMM and take several readings of voltage at several different locations. The instrument gauge could be throwing you. Also do this to check the acual amperage coming from the alternator.
Hope this helps!
Hope this helps!
02-21-2007, 06:45 PM
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The alt test that was done on it yesterday gave a reading down to 11 initially on rev and then up to a little over 13. I have a bad feeling about the exciter wire/plug.
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02-21-2007, 06:56 PM
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Sounds like the alternator. When mine went, I noticed at idle my voltage was low (guage reading low, lights dim, etc.)...I noticed that it would get better with higher RPMs, so I drove for the rest of the night in a gear or two lower than I normally would. Finally, it went dead and the volts didn't go up anymore, so I drove it home and parked it. Ordered a high-amp alternator off eBay, and a few days later it came and I installed it, and everything was back to normal.
02-21-2007, 07:20 PM
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Should I also look into the plug for the 'red wire'? What do you do, just get a new plug, unclip the old one and snap the wire into place and put it back into the alt?
02-21-2007, 07:22 PM
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if you have a dmm measure voltage from big red wire on alt. to pos. battery post (it should read 0 volts or very close to it. this test roles out wiring. also test the L termanial on alt it should at or near battery volts. if all checks good than u a have alt problem. good luck
02-21-2007, 07:25 PM
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Sounds like the alt to me.
Mine, when cold, would run fine. But as it warmed up it would give out. Had it down at the parts store a few times before finally figureing it out.
Mine, when cold, would run fine. But as it warmed up it would give out. Had it down at the parts store a few times before finally figureing it out.
02-21-2007, 09:09 PM
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I just ordered one from Advance, I think I may go there too often. They didn't even ask for the deposit or core. It will be in tomorrow at 4 pm. I am going to pull mine and bench test it over there before completing the purchase. I really hope at this point that it IS the alternator. Just an easy fix and be done with it.
02-22-2007, 11:32 AM
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Originally Posted by shouldaboughttheZ
Sounds like the alt to me.
Mine, when cold, would run fine. But as it warmed up it would give out. Had it down at the parts store a few times before finally figureing it out.
Mine, when cold, would run fine. But as it warmed up it would give out. Had it down at the parts store a few times before finally figureing it out.
Problem with that logic is that if you have a leak somewhere in your wiring, the alternator (which is just a big inductor) will be fine until the extra strain heats it up beyond normal operating temperature. This will ruin the coil. You can run through a number of alternators when it was a simple wiring problem.
A lot of ppl who have this problem and it's miraculously fixed by changing the alternator could have just had a bad connection on the exciter wire and when they changed the alternator they finally connected it correctly.
02-22-2007, 06:42 PM
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In and working well, just a touch over 13 when at idle and then steps up when the lights are used. I think it may take some time to get back up to 14 where it was after the Optima gets fully charged after a long enough drive. Thanks all!
02-22-2007, 07:04 PM
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Originally Posted by irnbru83
Problem with that logic is that if you have a leak somewhere in your wiring, the alternator (which is just a big inductor) will be fine until the extra strain heats it up beyond normal operating temperature. This will ruin the coil. You can run through a number of alternators when it was a simple wiring problem.
A lot of ppl who have this problem and it's miraculously fixed by changing the alternator could have just had a bad connection on the exciter wire and when they changed the alternator they finally connected it correctly.
A lot of ppl who have this problem and it's miraculously fixed by changing the alternator could have just had a bad connection on the exciter wire and when they changed the alternator they finally connected it correctly.
But you are correct, people do tend to overlook that wire.
