So i have a brand new alternator and battery, put them in and about an hour later of driving, my jeep started to limp along and had no response or power and wouldnt shift. Hooked it to jumper cables and would operate perfectly. Traced down all power wires and ground to discover power wire from alternator to starter/ignition relay was fried. (Previous owner spliced a 10 guage wire to the 4 guage off the alternernator.) While running now, voltage goes no higher then 11 when it should read 14, but only when running. As soon as power is shut off, the battery will jump back to 12v.. My opinion is something with starter relay or NSS.. Any advice?

 

Sumthin' ain't right here. There shouldn't be a 4 gauge wire off the alternator. Where does this wire go?

Yours may be a bit different from later Jeeps, but the basics shouldn't be far off. You should have 6 gauge from the battery + to the starter, and 6 gauge from the battery - to the engine block. That's factory, anyway.

There's also... something like an 8 gauge or may be it's 10 gauge going from the battery - to the fender, and another 8 or 10 from the battery + feeding power to the vehicle.

Alternator to battery + should be something like 10 gauge. There is NO reason for a 4 gauge cable there! That's "I don't know anything except bigger must be better!" idiocy.

 

With the Renix it doesnt even have from the battery to the fender. The only ground to body is off the block to the fire wall. And it may have been previous owner. If you would have seen all the stupid stuff ive found wired to this Jeep, you would see why. These guys had those Vampire clips to extend wires instead of butt connectors... But all my grounds and power are good now.... I havent checked voltage from terminal to relay but im just trying to figure out why it isnt charging when running. It doesnt drain when off, Only running.

 

Check the little 2 wire plug at the alternator. Be sure the wires aren't backing out.

 

So i took a multimeter to it earlier today instead of battery tester.. The voltage jumps from 11.72 down to 1.3 and everything in between. Ill check those pins and wire when i get home but do you, or anyone have any other suggestions I can also check when i get back?

 

That fried wire might have something to do with a fried new alternator. At this point, you can't assume the alt is okay.

 

[QUOTE=BlueRidgeMark;3605192]That fried wire might have something to do with a fried new alternator. At this point, you can't assume the alt is okay.[/QUOTE

i had the alternator bench tested and still passed. I was worried about that as well. i drove it across my small back yard and it died when I put it in park and now when I crank it, the voltage got from 3 to 5 with no start and barely turning over. I seen in another thread guys talking about they had issues after replacing the alternator and battery until they changed the starter. Stating they could drive for like 20 to 45 minutes and it dies... I replied asking if they bench tested the starter but never got a reply. I just dont wanna throw money in it right now.