cherokeexj21

Hey guys I had to replace the alternator on my 04 WJ 4.0. when I replaced it I realized sometimes it's on the 14 on the volt gauge and other times it's alittle past the 14.. Is that ok?

dave1123

My WJ ruins about one needle-width above or below the 14 volt mark, depending on it's whims. If it's much above that, I too would be concerned.

Bustedback

Start worrying when you see 15-16 volts.

wingless

The FSM has a chart showing charging voltage versus ambient temperature.

The dash gauge is not as accurate as a multimeter for checking the charging voltage.

cherokeexj21

yea it's about 1 needle-width below 14 to about 1-2 needle widths above

cherokeexj21

I'll see if I can get my hands on a multimeter

wingless

Here is my topic showing my generator tested per the FSM.

Fred/N0AZZ

13.8V would be correct I think.

blueseasons

My needle sits, a needles width ahead or behind 14. When it's cooler out, the needle sits below 14. Warmer out, to the right of 14. Lower in the morning I think because it's recharging from the juice used to start the engine. I have noticed these variables on other vehicles that I have owned as well.

dave1123

A lot of it has to do with battery condition. A weak or shorted cell will cause the voltage to go higher.

blueseasons

I have one cell that looses water continually. Battery is less than 2 years old. I have to fill it up weekly. It holds a charge, and tests fine. I am assuming that there is something wrong, but can't determine what. I will keep filling it until it finally dies. It doesn't appear to affect where the needle sits. All the vehicles that I have ever had with gauges have shown variables. Different reading with lights on and off, heater on and off, A/C etc. Sometimes minor, but I tends to watch gauges like a hawk.

Bustedback

Replace that battery, that is not normal.

dave1123

^^this^^ You probably have a poor intercellular connection on that cell in the battery that's causing it to overheat. It will function normally but will overheat when taxed with the starter draw or any other major demand, like rear window defogger.

DEN1956

i fitted a volt meter to the interior of my XJ...and when the engine is running the meter shows 14.2 too 14.5 volts.. depending on load...hope that helps.

Fred/N0AZZ

You want to check it at the alt output.......After you buy a new battery.