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2000 Jeep Alternator issues...... #430903
08/07/09 09:10 PM
08/07/09 09:10 PM
Joined: May 2004
Posts: 433
St.Clairsville Ohio
EV2RUNNER Offline OP
mopar
EV2RUNNER  Offline OP
mopar

Joined: May 2004
Posts: 433
St.Clairsville Ohio
Hey All... Im sure everybody else is at the NATS! I had to work this weekend and my Jeep is being Chevylike this weekend...

Anyway It is sometimes charging at 14 Volts on the Guage then it will act like it Quits, drops down to 12-12.5 volts, then it will charge again. I took the alt off and took it in to Advance Auto, they tested it and it tested good..

So I figured battery must be bad, had battery tested. Rated at 875 CCa Only tested at 443 CCa , so I replaced the Battery... Guess what Still does it but now is staying at 12.5 volts and seems like alt isnt charging..\

So My Question is: Does anybody know
  • is this internally regulated?
  • What "Excites" The alt to start charging? Is it compueter controlled?
  • Is there a relay or fuse or anything between the power that excites the alt and the actual windings? Thanks


2000 Grand Cherokee 4 Liter I6

Re: 2000 Jeep Alternator issues...... [Re: EV2RUNNER] #430904
08/07/09 10:55 PM
08/07/09 10:55 PM
Joined: Oct 2005
Posts: 9,065
Milwaukee, WI
In_The_Pink Offline
master
In_The_Pink  Offline
master

Joined: Oct 2005
Posts: 9,065
Milwaukee, WI
You have a week-old PM to reply to...

Re: 2000 Jeep Alternator issues...... [Re: In_The_Pink] #430905
08/08/09 03:55 PM
08/08/09 03:55 PM
Joined: Mar 2007
Posts: 862
Southeast Pa.
SALEM1912 Offline
super stock
SALEM1912  Offline
super stock

Joined: Mar 2007
Posts: 862
Southeast Pa.
Could be worn brushes in the ALT. could be making contact and then lose contact. Next time its acting up rap it with a small hammer and see if it starts charging.

Re: 2000 Jeep Alternator issues...... [Re: EV2RUNNER] #430906
08/08/09 04:00 PM
08/08/09 04:00 PM
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
R
RapidRobert Offline
Circle Track
RapidRobert  Offline
Circle Track
R

Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
I'm thinking part time "open". I'd check all your connections for clean/tightness & clean the ECU ground as it could be marginal & intermittently making/breaking contact w the fender or firewall. Block grounds also


live every 24 hour block of time like it's your last day on earth
Re: 2000 Jeep Alternator issues...... [Re: EV2RUNNER] #430907
08/13/09 12:12 PM
08/13/09 12:12 PM
Joined: May 2004
Posts: 433
St.Clairsville Ohio
EV2RUNNER Offline OP
mopar
EV2RUNNER  Offline OP
mopar

Joined: May 2004
Posts: 433
St.Clairsville Ohio
OK Ive been racking my brain on this thing for awhile now. I Disassembled alt, brushes were good, I traced all the wiring clear back to the PCM everything was good , cleaned all grounds. Replaced Battery, Battery temp sensor, alternator, and still no charge. Only thing I could figure was the part of the PCM that acts as the "Voltage Regulator" is bad.

Long story short dealer wants big$$ for a new computer and to flash all my info onto the new one, found one used for $200 But Dealer still must program it to my car.This thing has 130,000 mi on it its no jewel..

Did some research on the charging system, found that it is the same basically as the post '70 Mopars. Negative field wire is interrupted by the PCM to contol voltage at 14.5...Just as the voltage regulator does on our old mopars.

So guess what? Under the hood of my 2000 Grand cherokee, right next to the PCM resides a Mopar Voltage Regulator. Works like a charm. Just ran the Red wire on the VR to Ignition Hot, and the Green from the VR to the -Field trigger wire on the Alt. (Green) Left the Alt Source wire to the PCM alone (Lt. Blue/Black) So the PCM still reads alt output, and everyones happy.No Codes either!

Re: 2000 Jeep Alternator issues...... [Re: EV2RUNNER] #430908
08/13/09 12:27 PM
08/13/09 12:27 PM
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
R
RapidRobert Offline
Circle Track
RapidRobert  Offline
Circle Track
R

Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
Quote:

So guess what? Under the hood of my 2000 Grand cherokee, right next to the PCM resides a Mopar Voltage Regulator. Works like a charm. Just ran the Red wire on the VR to Ignition Hot, and the Green from the VR to the -Field trigger wire on the Alt. (Green) Left the Alt Source wire to the PCM alone (Lt. Blue/Black) So the PCM still reads alt output, and everyones happy.No Codes either!


So much for technology , & people wonder why we luv our antique Mopars


live every 24 hour block of time like it's your last day on earth






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