Stranded, need alternator/ charging help

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Digger, as far as electricity goes, Im still wearing those little floaty things that you put on your arms.

However, I successfully followed everybody's directions, slowly, and narrowed it down to the computer.

After I ruled out everything else, I decided to take the computer apart. I cant remember how to post pictures but its nothing exciting. A burnt chip with a little bit of charring.

So, now what? Is there a way to fix this? Could I take it to an auto electrician or would they even mess with it. Or am I doomed getting a new computer?

 

[Digger87xj]

not usually repairable locally

I use these guys a lot, mostly for WJs but they have yours too

Auto Computer exchange

 

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Discount and Auto Zone (Napa was already closed) both quoted $240. for a reman, no new ones available.

Might be worth the extra $40 to have a store to walk into for the lifetime warranty.

 

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Also, when I enter my information, it brings up a "police" edition. Does anybody know what the difference is and if its compatible? More aggressive shift points? Higher top speed? (Not that mine has ever seen 70mph)

 

[Muddzz]

Is there a way to run an external voltage regulator, either bypassing the pcm or without screwing it up?

Some people have run a separate external voltage regulator, replacing the EVR. Haven't read much feedback of how it worked out as permanent solution, only that their battery is being charged.

The EVR is a variable rate type regulator integrated into the PCM and OE wiring. It's difficult to determine exactly what sort of data and i/o from the EVR is used in the PCM's programming for emissions and to run the engine.

There is one website that sells an external voltage regulator kit.

http://store.alternatorparts.com/hd-external-voltage-regulator-conversion-field-replacement-kit.aspx

One problem with the integrated PCM / EVR design. If something connected to the PCM's wiring harness and/or the PCM (EVR) stops functioning you may end up stranded somewhere with a dead battery.

Your EVR can be functioning ok, however if the field voltages are being effected somehow, then your alternator may start to undercharge or overcharge leaving you with electrical problems, damaging the battery, etc.

After having charging problems I installed one as a backup regulator, in case something goes wrong with the oe wiring and charging system, the Jeep will still have a working alternator.

 

[Muddzz]

Here are some possible codes related the alternator and charging system that the PCM may produce.

As you can see the PCM (EVR) monitors alternator voltages. If I were to permanently install an external voltage regulator or another type of alternator. The PCM may indefinitely produce DTCs.

Voltage is regulated by cycling the ground path to control the strength of the rotor magnetic field and the alternator's output. It does this based on voltage and temperature inputs. (The internal design of the alternator and output is based partially on engine rpms.)

Charging system DTCs

P0622-GENERATOR FIELD NOT SWITCHING PROPERLY.
P1492-AMBIENT/BATT TEMP SEN VOLTS TOO HIGH.
P1493-AMBIENT/BATT TEMP SEN VOLTS TOO LOW .
P1594-CHARGING SYSTEM VOLTAGE TOO HIGH .
P1682-CHARGING SYSTEM VOLTAGE TOO LOW. .

When Monitored and Set Condition:

P0622-GENERATOR FIELD NOT SWITCHING PROPERLY
When Monitored: With the ignition key on and the engine running.
Set Condition: When the PCM tries to regulate the generator field with no result during monitoring.

P1492-AMBIENT/BATT TEMP SEN VOLTS TOO HIGH
When Monitored: With the ignition key on.
Set Condition: The PCM senses the voltage from the AMBIENT/BATT temperature sensor to be above 4.9 volts for 3 seconds.

P1493-AMBIENT/BATT TEMP SEN VOLTS TOO LOW
When Monitored: With the ignition on.
Set Condition: The PCM senses the voltage from the AMBIENT/BATT temperature sensor to be below 0.5 volt for 3 seconds.

P1594-CHARGING SYSTEM VOLTAGE TOO HIGH
When Monitored: With the ignition key on and the engine speed greater than 0 RPM.
Set Condition: When the PCM regulates the generator field and there are no detected field problems, but the voltage output does not decrease.

P1682-CHARGING SYSTEM VOLTAGE TOO LOW
When Monitored: With the ignition key on and the engine running over 1500 RPM after 25 seconds.
Set Condition: When the PCM regulates the generator field and there are no detected field problems, but the voltage output does not increase.