WillieD Evo X

Sorry for the vague tittle but I'm at my wits end on this one,

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 receiving a decent 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 (picture #1). Anyway I threw 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, so I took my old alternator in to be tested just to see what's going on and it passed. We ran the system for codes and it kicked back B210A & B2353 cleared them, and ran the test again and they didn't pop but the warning was still there.

My thought process right now is to disconnect the battery in the rear and attach it to the positive spot in the front and ground it to the frame, turn the car on and if the warning goes away then I have a break in the system. If that doesn't work then I was going to run a wire from the positive wire that is connected to the alternator and the positive clip in the trunk and see if its a closed system with a multi meter, I'm not electrical savvy so all this is just random guessing at this point..........yeah, help please

splattj

iTrader: (2)

So the alternator output is controlled by a circuit in the ECU as is the diagnosis function. If the alternator is ok on the bench, it could be wiring, a fuse, or an ECM problem. Here's the shop troubleshooting guide:

CHARGING SYSTEM DIAGNOSIS

TROUBLESHOOTING HINTS
Generator malfunction light does not go on when the ignition switch is turned to ON, before the engine starts.
Check the generator malfunction light.•

Generator malfunction light does not switch off after the engine starts.
Check the IC voltage regulator inside the generator.•

Discharged or overcharged battery.
Check the IC voltage regulator inside the generator.•

TROUBLESHOOTING GUIDE
The charging system troubleshooting guide is shown in the following steps.

STEP 1.
Q:Is the battery in good condition? (Refer to GROUP 54A, Chassis Electrical − Battery − On-vehicle Service − Battery Test P.54A-9.)

YES : Go to Step 2.
NO : Charge or replace the battery.

STEP 2.
Q:Is the generator drive belt in good condition? (Refer to GROUP 00, General − Maintenance Service − Drive Belts (For Generator, Power Steering Pump and Air Conditioning) (Check) P.00-66.)
YES : Go to Step 3.
NO : Adjust the belt tension or replace the belt.


STEP 3.
Qoes the generator malfunction light come on when the ignition switch is turned on?
YES : Go to Step 4.
NO : Check the ignition switch. (Refer to GROUP 54A, Chassis Electrical − Ignition Switch − Ignition Switch − Inspection P.54A-22).Check the generator malfunction light and its related circuits.Check the generator. (Refer to Charging System − Generator Assembly − Inspection P.16-20).

STEP 4.
Qoes the generator malfunction light go out after starting the engine?
YES : Go to Step 5.
NO : Check the generator (Refer to Charging System − Generator Assembly − Inspection P.16-20.)

STEP 5.
Q:Is an oscilloscope available?
YES : Go to Step 6.
NO : Go to Step 7.

STEP 6.
Qoes the oscilloscope show a normal wave pattern? (Refer to Charging System − On-vehicle Service − Wave Pattern Check Using an Oscilloscope P.16-11.)
YES : Go to Step 7.
NO : Check the generator. (Refer to Charging System − Generator Assembly − Inspection P.16-20.)

STEP 7.
Engine: 2,500 r/min•
Headlight: ON (high beam)•
Voltage between generator terminal B and the positive battery terminal
OK: 0.5 V or less
Voltage between the negative battery terminal and generator body
OK: 0.5 V or less

Q:Are the generator output line and ground line in good condition?
YES : Go to Step 8.
NO : Check the generator output line and ground line.

STEP 8.
Q:Is the output current normal? (30-40 amps at 2500RPM)
YES : Go to Step 9.
NO : Check the generator

STEP 9.
Q:Is the regulated voltage normal? (14v-15v DC)
YES : Go to Step 10.
NO : Check the generator

STEP 10.
Q:Is the voltage drop in the generator output line normal?
YES : Generator is normal. Check other systems.
NO : Check the output line.

Burnhad91

I like to check easy things first! Make sure you have battery voltage at the BAT post on the alternator and small blue wire for the voltage regulator. 9 times out of 10 you'll get lucky and have a bad fuse or fusible link

WillieD Evo X

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!

WillieD Evo X

Thank you for the replies and help i'm stll trying to wrap my head around this electrical stuff (i'm a noob at this evo stuff)

Spazm

I dont think this is going to get you anywhere. If the main cable from the trunk to the power block up front was open you would have no power at all.

Find the fuse for the ALT output (appears to be a fusible link). If there is battery voltage at the large wire connecting to the alt, then assume the link is fine. Start the car and compare voltage at the output at the ALT vs power block. If they are the same move on, no fault. If ALT is higher, the problem lies in the the large cable connected to the ALT.

Also the fuse for the ALT field windings. Looks like fuse #5(dont hold me to that) in engine compartment fuse block. 7.5A This appears to be the blue wire coming from the connector on the back side of the ALT. If you can back probe it with the engine running battery voltage should be present here as well.

If the voltages check out, testing the wires in the connector is the next step.

edit: it appears you made an update while i was busy googling the wire schematics. I also have an explanation for your conflicting ALT test slips. The first one was a bench test. The testing unit energizes the field windings itself. The second one looks like an in-car test. I am going to say the field circuit has a fault in it. (likely a fuse).

WillieD Evo X

When you say field circuit do you mean the fuse in the Alternator or something entirely different, sorry for the repetitive question just trying to grasp the understanding of the electrical world so I can apply it to my problem and solve it

Spazm

there is no fuse in the ALT itself. Just a voltage regulator.

The field windings are the coils of wire that when powered up create a magnetic field. The stator coils are the wires you can see moving when you spin the ALT by hand. As they pass through the magnetic field it induces a current in the stator coil. This is what gets output as charging voltage. (after some diodes change it from AC current into a real choppy DC.)

If the fuse for the field windings is blown, there will be no magnetic field to induce a current in the stator (the spinny part.) It is very possible that your old ALT field windings shorted out and popped the fuse.

WillieD Evo X

Understood I'll check it out fuse #5 in the morning asap! thank you for the information =D

WillieD Evo X

Ok so I got an itch and the fusible link didn't sit right with me, I swapped it out for my friends. Now the alternator when I tested it with the 20v multimeter it's reading 15.33 then I measured the alternator to the postive point on the fusible link and got -0.05. So I got really curious and tested the battery 14.75. Mind you before I swapped the fusible link I was reading 7.9 at the alternator and 12 at the battery. Now the charge service due light is still on no codes but I assume if I drive around it will fall off.

WillieD Evo X

drove it today light still on thinking of taking it to the dealer tomorrow and have them look.