2007 JK keeps burning up alternators

Matt2009

Matt2009

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West Virginia
I have a 07 jeep wrangler(jk) 3.8L in the shop that seems to keep burning up alternators. Charging at 14.5+ at all times causes them to get hot and burn up. I've tried a new pcm, new wire from alt to battery, new battery terminals, ground cable straight to alternator housing, checked all other grounds. I read the tipm also controls the charging system? Any advice would be appreciated
 
Are you putting on new or rebuilt alternators? 14.5 shouldn't be burning up a alternator that is a normal charging volt.
 
How many amps are being produced? 14.7 should be standard volts with a fully charged battery. Have you load tested the battery?
 
I haven't tested the amps. 14.5v is being produced but its like it won't shut off. I read another post guy had the same issue he replaced alt, battery and all leads to get his fix.. I just bought a battery. Going to try it and the leads. Autozone tested the battery good but its worth a shot.
 
Cleaned all 3 grounds to pcm,battery,tipm with no prevail. Pulled tipm connects apart didnt see any burn or corrosion. Disconnected starter wire with it running didnt change a thing so starter doesn't have a short. New battery. Didnt change anything. New ground cable to the block no change. This leads me to believe the tipm itself is the issue.
 
I did some research. (Broke my foot in August and have nothing better to do.) The tipm and PCM work together to regulate the voltage. From what I can find, the manufacturer has not let anybody know how it does this yet.
At this point, sadly, it seems you are our guinea pig.
 
JKTim said:
I did some research. (Broke my foot in August and have nothing better to do.) The tipm and PCM work together to regulate the voltage. From what I can find, the manufacturer has not let anybody know how it does this yet.
At this point, sadly, it seems you are our guinea pig.
Click to expand...


He says that it has 14.5 volts and that's what my JK has all the time, i'm wondering if he's getting a voltage spike. The only way to know would be to mount a volt gauge where he can watch it.

You can put a external voltage regulator on or there's a company that sells a 1 wire alternator with a built in regulator. But the problem with that your going to have the CEL on all the time.
 
If it is reading low voltage the amps increase to raise the voltage up to the regulated 14.5 volts. It isn’t the voltage that is creating the heat. It is the abundance of amperage “burning up” the alternator. One would need to monitor how many amps are being produced to maintain the 14.5 volts to get a better understanding of what is happening.
 
One test to try, how many volts are at the TIPM power feed connection as opposed to at the alternator output stud. Or check resistance of the positive battery cable. I’m sure it is a spiderweb looking monster. It would need to be unhooked from every connection and resistance tested between all points. Eliminating a voltage drop seen by the system creating an increase in amperage.
 
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