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Any info on alternator? New, used, one wire, 3 wire, stock amp?

If no help here, maybe post in electrical section?
 

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Discussion Starter #3 (Edited)
It's a new (rebuilt) 3-wire unit from Oreilly's. I believe it's the stock amp.

I forgot about the electrical section, sorry. Mods, you can move this if you need to.
 

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If the internal regulator is not working properly the alternator will work to hardand can over heat. It can also ruin your battery. Remember just because it is new doesn't mean it can't be bad.
 

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I forgot about the electrical section, sorry. Mods, you can move this if you need to.
Hope you don't think I was telling you this was posted in wrong place. There is a lot of great help in 4th gen's, but not everybody looks at the posts here. :)
 

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Discussion Starter #7
Hope you don't think I was telling you this was posted in wrong place. There is a lot of great help in 4th gen's, but not everybody looks at the posts here. :)
Not at all, but you're right, it would get more ewxposure in the electrical section.

Anyway, I had it tested and it passed :confused:. So I took it back home, put it on, fired it up and it ran fine! Until we accidently tried to put the battery cables on backwards :rolleyes:. The alternator sparked pretty good, and when we ran it again it got really hot. I think I may have damaged it, but I'm not sure.
 

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Alternators will generate heat, that is why they have the little fan behind the pulley. However smoke should not be coming out of it. A quick check to see if it is working is to measure voltage at the battery. With the key off measure battery voltage, then measure again with the engine running. Running should be 1.5 - 2.0 volts higher, not to exceed 15 and ideally be around 14.2- 14.5.
 

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Discussion Starter #9
I have had alternators get pretty warm, but this one will melt skin, so somethings definately wrong. I will try to check the output tonight, but I think I may have fried the regulator when I switched the battery cables.
 

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Sounds like a sulfated battery to me. (Internally shorted). There is a test for this problem-you won't find it in any books. Put a battery charger on the battery (not a trickle charger); while the battery is charging put a volt meter across it, if the volt meter reads above 16 volts the battery is sulfated or shorted. Replace asap. What is really happening, the alternator is trying to keep the battery up so it is full fielding (max output) all the time. It can't put out 16 volts to keep the battery up. That is why the alternator gets so hot. Also, when this happens the alternator gets hot very quickly, enough that you can not touch it with your hands.
 

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Discussion Starter #11
I had the old battery tested with the alternator and it was a little low so I bought a brand new battery last night. It worked the first time, but after the cables got crossed the alternator got hot again.
 

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When you momentarily hooked the battery backwards, it burned out the diode.
When it's bench tested, it may show charge, but it should also be static tested with an ohm meter. Even if it was your fault (don't tell them what you did), they'll still warrent it.
 
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