Chrysler Repair: 93 Jeep charging problem: code 41, jeep cherokee, field coil

Question
I have a '93 Jeep Cherokee 4.0, while driving yesterday, my car lost a lot of electrical power, and the check engine light came on so I ran the ignition codes and got 41. I have recently replaced the alternator so I figured that wasn't it. The battery wasn't in the best shape so I put a new battery in today. I had the alternator tested twice, and it came back at 13.6 and 14.2(14.2 was today after the new battery was installed) Unfortunately the car still seems to be not getting any power from the alternator, the check engine light is still on, and the volt gauge on my dash is pretty low. Should I replace the wires or just drive my car off a dock and go purchase a bike?

-Jeremy

Answer
Hi Jeremy,
I don't have the wiring diagrams for the Jeep, but if it is similar to Chrysler I would trace the wires assigned to the field coils of the alternator because that is what the 41 code is referring to. Basically, one of the four wires at the alternator should have 12V applied on it when you turn the ignition switch to "run"; that is the source of voltage for the field coil. Then another wire should go to the engine controller, and that one should oscillate due to the controller's action between 0V and 12V which is what modulates the field coil so that the output of the alternator averages at around 14v when the engine is turning it over. The other two wires are a fat ground and of course the fat 12v wire to the battery directly. The code is saying that there is a short (presumably to ground) on either of those first thinner two wires so that there is no magnetic field being established in the field coil.
I hope you can sort out the wires without having the color codes.
In any case, it is always healthful and economical to have a bike for errands, so I won't discourage you from getting one of those! I ride mine locally every day.
Roland