Alternator charging to much?
Thread Starter
Member
Joined: Dec 2014
Posts: 167
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From: Ct
Year: 2004
Model: Grand Cherokee
Engine: 4.0
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?
Old fart with a wrench
Joined: Nov 2010
Posts: 14,398
Likes: 740
From: Manlius, east of Syracuse, NY
Year: 2000 XJ Sport & WJ Laredo
Model: Grand Cherokee (WJ)
Engine: 4.0L
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.
Senior Member
Joined: May 2015
Posts: 818
Likes: 35
Year: 1994
Model: Grand Cherokee
Engine: 5.2L Magnum V8 220hp 285ft-lbs
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.
The dash gauge is not as accurate as a multimeter for checking the charging voltage.
Thread Starter
Member
Joined: Dec 2014
Posts: 167
Likes: 0
From: Ct
Year: 2004
Model: Grand Cherokee
Engine: 4.0
Thread Starter
Member
Joined: Dec 2014
Posts: 167
Likes: 0
From: Ct
Year: 2004
Model: Grand Cherokee
Engine: 4.0
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Senior Member
Joined: Sep 2013
Posts: 518
Likes: 3
From: Santa Cruz Ca.
Year: 2000 WJ
Model: Grand Cherokee
Engine: 4.7
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.
Old fart with a wrench
Joined: Nov 2010
Posts: 14,398
Likes: 740
From: Manlius, east of Syracuse, NY
Year: 2000 XJ Sport & WJ Laredo
Model: Grand Cherokee (WJ)
Engine: 4.0L
A lot of it has to do with battery condition. A weak or shorted cell will cause the voltage to go higher.
Senior Member
Joined: Sep 2013
Posts: 518
Likes: 3
From: Santa Cruz Ca.
Year: 2000 WJ
Model: Grand Cherokee
Engine: 4.7
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.
CF Veteran
Joined: Feb 2010
Posts: 12,367
Likes: 23
From: Oroville, CA
Year: 1995
Model: Grand Cherokee
Engine: 4.0 with all of the noise and clatter
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.
Old fart with a wrench
Joined: Nov 2010
Posts: 14,398
Likes: 740
From: Manlius, east of Syracuse, NY
Year: 2000 XJ Sport & WJ Laredo
Model: Grand Cherokee (WJ)
Engine: 4.0L
^^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.



