Tylan
Well-Known Member
Alright, here we go again.
I've had this problem for a while, and it's really been messing with my head the whole time.
I asked about it in this other thread about a year ago now, where 67dart and Mattax tried their best to help, but unfortunately to no avail.
I recently got inspired to tackle this again, and went as far as just ripping out the interior wiring harness, which wasn't really too bad. By doing this I could get a better grasp and test the resistance of every single wire; which by the way, every wire in this harness seemed to be within reasonable ohm readings, under 1 ohm.
Then, since I had a better view of every wire in the harness, completed only the blue alternator field circuit (at least up to the alternator), shown by this diagram given by Mattax in the other thread: A1A-10R > 12-BK > Ignition switch > Blue run wire > J2 (only the blue wire connecting to the alternator)
This isolation test showed that this lone circuit is good, since it had the same voltage as the battery, albeit with a insignificant 0.05 volt drop. Adding in only the volt regulator (J2B) and ignition module (J2A) didn't cause any significant voltage drops when probing the same field wire from before. It was only until I reconnected the ignition coil did the voltage drop I know and hate occur.
So far, the situation has been whether or not the engine is running, if everything minus the radio, heat/ac control module and heater fan, as well as the wiper motor, is connected, the battery would show 12.3-12.4 volts, while running. And the blue alternator field wire would be getting closer to 11.8 volts. I could be wrong, but I imagine the fact that the alternator field getting less voltage than the battery itself holds is the reason why the alternator is not charging the system.
When doing my recent test, today in fact - and remember, it is just the ignition coil and blue field circuit containing power for this particular test, with the engine off - I get the same readings: 11.8-11.9 volts at alt. field, 12.3-12.4 volts at battery. I also probed the positive post of the ignition coil - not sure why I didn't do this before - and it read closer to 6 volts (which is normal I believe, and not of concern of mine unless that is, in fact, off).
So, my dilemma is: field wire not getting full battery power with ignition parts plugged in, which I know now, rather than being clouded with so many possibilities, because this time I've narrowed down the problem area. Is there an issue with my ignition module? voltage regulator? ignition coil? The ignition module and voltage regulator are pretty damn new, so I wouldn't immediately point them out as the problem, but still not eliminating them as possibilities.
But here's an important question: do I even have a problem at all, or am I chasing a phantom issue, making an issue where there is none? I was certain, no matter the year, a 12v system using a 12v battery should always charge the battery to around 13 to 14 volts if functioning properly, but I suppose I could be wrong.
I've had this problem for a while, and it's really been messing with my head the whole time.
I asked about it in this other thread about a year ago now, where 67dart and Mattax tried their best to help, but unfortunately to no avail.
I recently got inspired to tackle this again, and went as far as just ripping out the interior wiring harness, which wasn't really too bad. By doing this I could get a better grasp and test the resistance of every single wire; which by the way, every wire in this harness seemed to be within reasonable ohm readings, under 1 ohm.
Then, since I had a better view of every wire in the harness, completed only the blue alternator field circuit (at least up to the alternator), shown by this diagram given by Mattax in the other thread: A1A-10R > 12-BK > Ignition switch > Blue run wire > J2 (only the blue wire connecting to the alternator)
This isolation test showed that this lone circuit is good, since it had the same voltage as the battery, albeit with a insignificant 0.05 volt drop. Adding in only the volt regulator (J2B) and ignition module (J2A) didn't cause any significant voltage drops when probing the same field wire from before. It was only until I reconnected the ignition coil did the voltage drop I know and hate occur.
So far, the situation has been whether or not the engine is running, if everything minus the radio, heat/ac control module and heater fan, as well as the wiper motor, is connected, the battery would show 12.3-12.4 volts, while running. And the blue alternator field wire would be getting closer to 11.8 volts. I could be wrong, but I imagine the fact that the alternator field getting less voltage than the battery itself holds is the reason why the alternator is not charging the system.
When doing my recent test, today in fact - and remember, it is just the ignition coil and blue field circuit containing power for this particular test, with the engine off - I get the same readings: 11.8-11.9 volts at alt. field, 12.3-12.4 volts at battery. I also probed the positive post of the ignition coil - not sure why I didn't do this before - and it read closer to 6 volts (which is normal I believe, and not of concern of mine unless that is, in fact, off).
So, my dilemma is: field wire not getting full battery power with ignition parts plugged in, which I know now, rather than being clouded with so many possibilities, because this time I've narrowed down the problem area. Is there an issue with my ignition module? voltage regulator? ignition coil? The ignition module and voltage regulator are pretty damn new, so I wouldn't immediately point them out as the problem, but still not eliminating them as possibilities.
But here's an important question: do I even have a problem at all, or am I chasing a phantom issue, making an issue where there is none? I was certain, no matter the year, a 12v system using a 12v battery should always charge the battery to around 13 to 14 volts if functioning properly, but I suppose I could be wrong.