Hello, Ive got a 93 ZJ the other day while driving stopped at a stop light and noticed the battery gauge went to 9 and has stayed there. I drove it home thinking it was the altenator toke it off an toke it oreillys and it passed their test twice took battery to wal mart and it was bad put the new one in and cleaned the cables put brass terminals on both neg and pos. Fired it up and it still just above 9 on the battery guage. put voltmeter on its 11.92 while idleing any ideas?

 

It could still be the alternator, are you getting any codes (41 alt field not switching correctly)?

 

Best I recall the Alt is controlled via the PCM. If there is a problem there, it will appear the Alt is dead.

Ron

 

Mine does the exact same thing. So I hooked up an external volt gauge and everything shows normal on the new gauge but shows very low in the dash.

 

try an inexpensive volt gage at Harbor freight about $19 to see if that will give you a different reading.. It should read about 14.2 volts when driving or more when above idleing. if not then alt is bad.. just had the same problem only with starter.. had tested said it was OK.. chased tail for 8 hours finally decided to just relpace the starter anyway and for joy no more problem.. Starts every time. Just my 2Cents worth..