new alternator is only cranking out 12.3 volts. is that good?
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Car: 1986 camaro Sports Coupe
Engine: L31 350
Transmission: 89 700R4
Axle/Gears: 3.42 gov lock
new alternator is only cranking out 12.3 volts. is that good?
I just replaced my alternator today because I broke the housing on my old one. But with my new alternator I'm showing below the half mark on the gauge and am only putting out 12.3 volts. Now I'm use to my old alternator running at like 14 volts or the mark after the 13 mark on the guage. Does this sound normal? I will say that my old alternator was clocked wrong so when I went to remove the belt, the back post on the alternator hit my intake and started sparking, then my positive battery terminal started to smoke. Any ideas where I need to be heading ?
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Car: 1989 camaro rs convertable
Engine: 305 tbi
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Axle/Gears: 7.5"3.42 gears forth gen 2000 camar
Re: new alternator is only cranking out 12.3 volts. is that good?
it should be around 13.8 but id check it with a meter.the car volt meter aren't very good.
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Car: 1986 camaro Sports Coupe
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Axle/Gears: 3.42 gov lock
Re: new alternator is only cranking out 12.3 volts. is that good?
I put an actual battery tester with a load and that's what it was showing and showed the battery was good. But the battery terminal smoke when the old alternators post hit the intake is what is bothering me.
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Re: new alternator is only cranking out 12.3 volts. is that good?
You may have blown a fuse inline with the alternator. 12.3v is the voltage of the battery, that alternator isnt getting ANYTHING to the battery if that's what it's showing while the car is running. There are some wires that go from the positive battery terminal over to the alternator that have some fusible links in them, check those to see if they're blown. Or you can just, with the car off, check resistance through that wire with a volt meter.
If you dont believe it and think the alternator is working, disconnect the battery while it's running. If the engine turns off, the alternator isn't getting any power to the electrical system. If the engine IS running, that means the alternator is working.
I imagine you probably blew the fuse links in that wire going from the alternator to the battery. I did the same thing years ago and just spliced that wire together. I tried a few different fuses there but tehy all blew eventually and I couldnt figure out where to get a fuse link like the factory one so I just gave up on it. I'd suggest you try to find a better solution than just bypassing that fuse, but thats what I ended up doing.
If you dont believe it and think the alternator is working, disconnect the battery while it's running. If the engine turns off, the alternator isn't getting any power to the electrical system. If the engine IS running, that means the alternator is working.
I imagine you probably blew the fuse links in that wire going from the alternator to the battery. I did the same thing years ago and just spliced that wire together. I tried a few different fuses there but tehy all blew eventually and I couldnt figure out where to get a fuse link like the factory one so I just gave up on it. I'd suggest you try to find a better solution than just bypassing that fuse, but thats what I ended up doing.
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dmccain (03-04-2021)
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Car: 87 bird
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Re: new alternator is only cranking out 12.3 volts. is that good?
you should not check the wire resistance with it in the circuit. disconnect either end. if there is a blown fuse link you could go to a junk yard and get a good one.
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Re: new alternator is only cranking out 12.3 volts. is that good?
More and likely your fusible link is blown.
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dmccain (03-04-2021)
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Re: new alternator is only cranking out 12.3 volts. is that good?
Also shows one of the reasons why you disconnect the battery when working under the hood.
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Re: new alternator is only cranking out 12.3 volts. is that good?
Sound advice Rich.
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Re: new alternator is only cranking out 12.3 volts. is that good?
Fusible links are simply wire. When replacing links, get a new on from a parts store. Do not recycle old ones
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Car: 1986 camaro Sports Coupe
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Axle/Gears: 3.42 gov lock
Re: new alternator is only cranking out 12.3 volts. is that good?
Well I followed the wire from the alternator back to the front of my car and there wasnt any links between it. It was a solid wire going from the alternator to a little black plastic distribution block by my headlights. I removed the wire from it and connected it the positive on my battery and its charging now. Reads over 13 volts on the gauge. And trust me, I know about in hooking the battery but I got in a hurry.
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Car: 1985 Volvo turbodiesel
Engine: 1989 305 TPI in the Volvo
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Re: new alternator is only cranking out 12.3 volts. is that good?
Disconnecting battery wire while car is running will damage/destroy the diodes, bad idea. If its charging at 13.8 or so, and the battery stays charged, you got lucky.
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Car: 85 Silver Iroc, 79 Camaro
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Re: new alternator is only cranking out 12.3 volts. is that good?
That black junction block you're talking about is the fusible link. It looks like a molded plastic collar.
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Car: 85 Silver Iroc, 79 Camaro
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Re: new alternator is only cranking out 12.3 volts. is that good?
A wire may not wear out, but the older wires used on cars are thicker stranded wires and are more prone to breakage.
I've been wiring all sorts of vehicles since I was a late teenager. I've been to both Rockford Fosgate's and Audio Control's wiring schools. I now wire limos and emergency vehicles. I go to SEMA each year and meet with all sorts of companies and new vendors. We all seem to have the same consensus.....
Being that old, thick stranded battery cables are garbage. Newer multi-strand wires are far superior in load carrying ability and flexibility.....but they are harder to work with to make solid connections. I've learned a TON from these companies and bring that to the table when I wire anything.....a car, motorcycle, boat or limo.
With all that being said, a wire doesn't actually wear out, but over time and exposure to heat they become brittle and prone to breakage. If you can, replace older wiring. But for originality, keep the OEM stuff.....just don't be surprised if it fails, eventually.
I've been wiring all sorts of vehicles since I was a late teenager. I've been to both Rockford Fosgate's and Audio Control's wiring schools. I now wire limos and emergency vehicles. I go to SEMA each year and meet with all sorts of companies and new vendors. We all seem to have the same consensus.....
Being that old, thick stranded battery cables are garbage. Newer multi-strand wires are far superior in load carrying ability and flexibility.....but they are harder to work with to make solid connections. I've learned a TON from these companies and bring that to the table when I wire anything.....a car, motorcycle, boat or limo.
With all that being said, a wire doesn't actually wear out, but over time and exposure to heat they become brittle and prone to breakage. If you can, replace older wiring. But for originality, keep the OEM stuff.....just don't be surprised if it fails, eventually.
#15
Re: new alternator is only cranking out 12.3 volts. is that good?
I just replaced my alternator today because I broke the housing on my old one. But with my new alternator I'm showing below the half mark on the gauge and am only putting out 12.3 volts. Now I'm use to my old alternator running at like 14 volts or the mark after the 13 mark on the guage. Does this sound normal? I will say that my old alternator was clocked wrong so when I went to remove the belt, the back post on the alternator hit my intake and started sparking, then my positive battery terminal started to smoke. Any ideas where I need to be heading ?
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