battery alternator regulator ???

OK, I'm a dumass. I searched. Just got back from a trip and went to drive home. Battery was dead. So i get someone to jump me and stupid me cant see in the dark and hook up the cables in REVERSE polarity. I know, me :hang:

This was with the good vehicle running and for about 10 sec. until i corrected the polarity. The jumper cables got hot. I didnt see any fire, or smoke, but could smell hot electronics. In the end, nothing bad happened to the other guys dodge truck AFIK. The jeep started right up afterward and runs fine. BUT...

The volt gauge reads 11V. With the engine running the terminals read 13.3V and with it off the battery reads 12.75V.

It's an optima red top and im guessing the reverse charge hurt it a little, but not that much cause it reads a nice 12.75V.

The 13.3V and 11V are what I'm worried about. Did i fry the alternator, votage regulator?


BTW, I'm so glad that the other guys car was Ok, that could have been bad! Not to mention if i fryed the new performance computer in my Renix XJ!

Thanks

13.3 is a little low, but it shows that the alternator is at least putting something out, so I'm guessing that you didn't fry the voltage regulator. If that happened, you'd probably get no voltage rise at all. Assuming you're using an accurate voltmeter, which seems likely given the spot-on reading of the battery at rest, my first guess is that you blew an alternator diode.

Matthew Currie said:

13.3 is a little low, but it shows that the alternator is at least putting something out, so I'm guessing that you didn't fry the voltage regulator. If that happened, you'd probably get no voltage rise at all. Assuming you're using an accurate voltmeter, which seems likely given the spot-on reading of the battery at rest, my first guess is that you blew an alternator diode.

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Thanks for the response...

An update:

After driving the jeep for a day everything seems back to normal. The running voltage is 14.5V and the battery is still @ 12.75V. I think I must be lucky.

jjvande said:

Thanks for the response...

An update:

After driving the jeep for a day everything seems back to normal. The running voltage is 14.5V and the battery is still @ 12.75V. I think I must be lucky.

Click to expand...

Yes, you're lucky.