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Discussion Starter #1
So here's the thing, last Sunday the "Charge Service Due" notification came across my dash along with the battery light. Confused I took the battery in tested fine did some research and bought a multimeter. Tested the car off and on and it seemed the batter wasn't reciving a charge. So I checked online and bought a alternator from another evo owner, it had 14k miles and came off a 2015. They sent the test receipt which I didn't see anything wrong with it. Anyway I through it in, that and a red top optima battery figured my problem would go away.....Yeah no, light is still there tested the alternator and it came up with these results (picture #2) now I don't think the alternator is bad but then again I don't know what to assume the problem is, I'm going to go get my original alternator tested and if it comes back as failed then it will help me figure out what the cause is. If it passes then well..........yeah, help please!!!
 

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Good luck. You did blow that fuse to that pump when we met so that could be an issue if the voltage or amperage is incorrect coming from the alternator.
 

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Just for shits and giggles did you check your Wrist Pins?
 

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Lol.
 

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Most likely battery. If not alt.
 

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Discussion Starter #10
Ok so update I've done a lot of test today, still don't have a clear concise answer. I wanted to see if maybe my fusible link had a break in the line to the battery. So I brought the battery up from the trunk to the front and connected it to the positive terminal at the front. I grounded it to the frame and still received the "charge service warning." I then put it back and ran a wire from the positive wire in the trunk and a separate off the alternator positive wire and tested it for ohms continuity. I heard anything less than1 ohm on the 20k setting on the multimeter is fine, the reading I had was 0.06, which would mean I have a closed system and no breaks. I started to get a little frustrated so I called it quits for today.

I have not gone over all the fuses and I forgot to check the voltage coming from the alternator while it is on, my guts are telling me its my ECU but i'm hoping tomorrow when I check it will be a bad fuse somewhere or even a bad connector on the fusebox inside the car. I pulled the OBDII reader out and there's no codes the only thing i'm getting is the battery light and the "charge system service due".......my head really hurts!
 

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Let us know. However I don't think it's your ecu. Also check via salt shaker method all of your relays.
 

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I then put it back and ran a wire from the positive wire in the trunk and a separate off the alternator positive wire and tested it for ohms continuity. I heard anything less than1 ohm on the 20k setting on the multimeter is fine, the reading I had was 0.06
An ohm meter wont always be truthful when telling you that a wire is ok or not. Meters use a very low voltage to extrapolate ohms in a circuit. If the large ALT cable only had 1 good strand left in a break or corrosion buildup the tiny bits of current from the meter will pass through just fine giving the illusion of no resistance. The piles of current the ALT produces, however, will see a restriction.

Think of it like one person walking through one door. No problem. 50 people and 1 door is a restriction.

I hope this isnt too confusing. You seem to be on the right track, I just dont want you to get caught up in a false positive test result.

There are 2 methods that I use for testing the condition of a wire. They are a voltage drop test and a regular load test. If you want to have a whack at it let me know. I will do my best to lay out the steps.

Most often if its not the ALT that failed its the field circuit. And the common field circuit failure is a fuse.
 

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Discussion Starter #13
An ohm meter wont always be truthful when telling you that a wire is ok or not. Meters use a very low voltage to extrapolate ohms in a circuit. If the large ALT cable only had 1 good strand left in a break or corrosion buildup the tiny bits of current from the meter will pass through just fine giving the illusion of no resistance. The piles of current the ALT produces, however, will see a restriction.

Think of it like one person walking through one door. No problem. 50 people and 1 door is a restriction.

I hope this isnt too confusing. You seem to be on the right track, I just dont want you to get caught up in a false positive test result.

There are 2 methods that I use for testing the condition of a wire. They are a voltage drop test and a regular load test. If you want to have a whack at it let me know. I will do my best to lay out the steps.

Most often if its not the ALT that failed its the field circuit. And the common field circuit failure is a fuse.
Thank you for breaking that down for me it made good sense, please if you have the time explain the other two methods and I will do my best to comprehend them and apply them to my current situation! =D
 

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Discussion Starter #14
Let us know. However I don't think it's your ecu. Also check via salt shaker method all of your relays.
I would really hope for it not to be my ECU I'm just referencing an earlier topic I found that has the same symptoms as I did, granted I'm not running a after market stereo system but I was running a turbo timer wired to the ignition (I have removed it since all this happened.)

http://www.evolutionm.net/forums/ev...679064-charging-system-issue-help-please.html
 

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First up will be the voltage drop test. The idea here will be to see how much voltage is lost in the wire. For this test you need a volt meter. Its just a 12v system so the 20v scale should be ideal. The circuit to be tested needs to be energized. In this case engine running. Put one lead black or red doesnt matter to the large cable at the ALT. Stick the other onto the power distribution block (there should be a stud with a nut poking straight up under the red plastic cover.) 0v means the wire is perfect and no voltage was dropped. 0.1v for a high amp cable like that is really good and means the wire itself consumed .1v. 0.5v is the upper end of Mitsu's spec. Anything more than .5v is a degraded wire. This test holds true for any wire in the car of any size. Just keep in mind dropping .1v at a connector is normal.

Load testing an ALT charging cable is not something i would normally do on account of the amount of amperage required. I like it better for testing the normal 16-20ga. wires used in control and sensor circuits that may not be a constant 12v. A wire that gets switched on and off can self induce a voltage. For this test i use an incandescent bulb. A halogen headlight works good but get hot very fast so be careful. (i use a dual filament stoplight/taillight bulb.) Disconnect both end of the wire to be tested. Connect one end to neg. and the other end to one of the bulb terminals/contacts. Bulbs dont care about pos. or neg. Connect the open terminal/contact on the bulb to pos. If the bulb lights up normal the wire is good. A dim bulb indicates a problem. Connect the bulb directly to power for the comparison. Higher amp circuits just add more bulbs in parallel.
 

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Discussion Starter #16
First up will be the voltage drop test. The idea here will be to see how much voltage is lost in the wire. For this test you need a volt meter. Its just a 12v system so the 20v scale should be ideal. The circuit to be tested needs to be energized. In this case engine running. Put one lead black or red doesnt matter to the large cable at the ALT. Stick the other onto the power distribution block (there should be a stud with a nut poking straight up under the red plastic cover.) 0v means the wire is perfect and no voltage was dropped. 0.1v for a high amp cable like that is really good and means the wire itself consumed .1v. 0.5v is the upper end of Mitsu's spec. Anything more than .5v is a degraded wire. This test holds true for any wire in the car of any size. Just keep in mind dropping .1v at a connector is normal.

Load testing an ALT charging cable is not something i would normally do on account of the amount of amperage required. I like it better for testing the normal 16-20ga. wires used in control and sensor circuits that may not be a constant 12v. A wire that gets switched on and off can self induce a voltage. For this test i use an incandescent bulb. A halogen headlight works good but get hot very fast so be careful. (i use a dual filament stoplight/taillight bulb.) Disconnect both end of the wire to be tested. Connect one end to neg. and the other end to one of the bulb terminals/contacts. Bulbs dont care about pos. or neg. Connect the open terminal/contact on the bulb to pos. If the bulb lights up normal the wire is good. A dim bulb indicates a problem. Connect the bulb directly to power for the comparison. Higher amp circuits just add more bulbs in parallel.
With it being the holidays i'm not sure if the local autozone or whatever will be open today, so I will try my best to obtain a volt reader, and when you say power distribution block do you mean the fusible links under the red positive cover?
 

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Discussion Starter #17
Also one more question does the ECU regulate the alternator? What I mean by that is so for instance the ECU was bad but I didn't know and I wanted to do a simple volt test on the alternator. Ground one lead and attach the positive lead to the positive bolt in the alternator. Will I get the actual reading of say 12v from the alternator or if the ECU is garbled will it already have altered the volts at the alternator? Say 9v.
 

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You could have a short. The alt should just be a constant voltage / amperage out.
 

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Also one more question does the ECU regulate the alternator? .
Yes - the function of voltage regulator is internal to the ECU.

BTW - there is a very complete and detailed troubleshooting charts / diagrams / steps in the FSM. Section 15-7, Engine, On-Vehicle Service, Generator ...

Testing of the ECU-Generator wires is also detailed in the Fsame SM section.
 

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when you say power distribution block do you mean the fusible links under the red positive cover?
yup

With it being the holidays i'm not sure if the local autozone or whatever will be open today, so I will try my best to obtain a volt reader
didnt you measure resistance already? most modern meters will measure volts, ohms, and amps.
 
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