Hey guys, I had the wiring to my 92 yj replaced and and it finally runs and drives 
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I towed it home from the mechanic because I knew it needing some tlc after sitting for a few months and didn’t want to risk breaking something. It had barely any coolant in the system when I went to drain it so I bought some Prestone radiator flush + cleaner. The bottle recommends for a thorough cleaning to run the engine on idle for 3-6 hours, I got to 2 hours and 3 minutes when I noticed the battery smoking (it was just a little steam but still enough for me to slightly panic and turn off the engine). My dad said it probably ran out of water is all, so the next day I filled it up with water and ran the engine. It wasn’t long before it did the same thing, so I turned the engine off. I thought it was the battery so I put my other battery in (which was dead so I had to jump start it) I tested the voltage when I got it running and the battery read 17 volts while running but 12.1 while off, so I knew it wasn’t the battery.
So I bought a knew alternator which is 90amps (I don’t know the amperage of the old one yet but I’ll be taking it to autozone tomorrow to find out) I installed the new one today and started it up and the battery still reads 17 volts…. Is this normal for a 1992 4.0L yj? And if not, do any of you know a fix? If the old alternator turns out to be a 90 amp one I can only assume that I need to buy a higher amperage alternator like a 136 amp. If that is the fix, will I also need to replace the alternator wires for bigger ones? Thank you guys in advance for your advice
.I towed it home from the mechanic because I knew it needing some tlc after sitting for a few months and didn’t want to risk breaking something. It had barely any coolant in the system when I went to drain it so I bought some Prestone radiator flush + cleaner. The bottle recommends for a thorough cleaning to run the engine on idle for 3-6 hours, I got to 2 hours and 3 minutes when I noticed the battery smoking (it was just a little steam but still enough for me to slightly panic and turn off the engine). My dad said it probably ran out of water is all, so the next day I filled it up with water and ran the engine. It wasn’t long before it did the same thing, so I turned the engine off. I thought it was the battery so I put my other battery in (which was dead so I had to jump start it) I tested the voltage when I got it running and the battery read 17 volts while running but 12.1 while off, so I knew it wasn’t the battery.
So I bought a knew alternator which is 90amps (I don’t know the amperage of the old one yet but I’ll be taking it to autozone tomorrow to find out) I installed the new one today and started it up and the battery still reads 17 volts…. Is this normal for a 1992 4.0L yj? And if not, do any of you know a fix? If the old alternator turns out to be a 90 amp one I can only assume that I need to buy a higher amperage alternator like a 136 amp. If that is the fix, will I also need to replace the alternator wires for bigger ones? Thank you guys in advance for your advice
