Alternator Control via MS3 wiring and settings help

[jsmcortina]

Use "High speed field switching" - I tested with a Jeep alternator which is likely very similar and that setting worked well.

I have some updates for the manuals pending, but I have been awaiting feedback from a vendor on some other testing.

James

[ntstlgl1970]

I tried that as well, same result, 18 volts with no control at all

[jsmcortina]

Are you sure you are wired to the correct pin? It worked great for me.
Plus.


James

[jsmcortina]

I double checked your MSQ and it looks to match the wiring you mentioned just fine.

Perhaps as a test, try a small bulb between 12V and the output. Then with the engine running, vary the target voltage up and down and see what the bulb does.

i.e. with 12.0V displayed on your TunerStudio dash, set the "Charge Mode" target above and below 12V (11.5 - 12.5 in 0.1V steps). Confirm with another TunerStudio dash gauge that the Alternator target voltage (outputs 3) is following your setting.

The bulb should light when the measured voltage is below target.

Please take a datalog during this testing and attach it.

James

[ntstlgl1970]

I did something similar when confirming the wiring with a test light on the field side, I will double check and see what it does.

[ntstlgl1970]

I did something similar when confirming the wiring with a test light on the field side, I will double check and see what it does.

I updated to v1.41 just in case there was an issue with the firmware install prior to testing..

well, the commanded voltage (on the dash) changes with the settings in tunerstudio, but the alternator still acts like it's full fielded all the time.

[jsmcortina]

Did you do the light bulb test?
EDIT: if that's ok, you may need a flyback diode across the field. 1N4001 likely ok.

James

[ntstlgl1970]

I Measured the field coil on my alternator (using alternator from an 09 challenger) and it measures 1.5 ohms. Upon reading the description of the circuit from chrysler, I was wondering if I can use the injector outputs from the 3.57 card to run the alternator field similar to what chrysler mentions here

I pulled the alternator off the car and did some checking, the wiring instructions are not valid for this alternator. The "field sense" pin is power to the rotor winding, the other end of the rotor winding is permanently grounded internally to the alternator case. The "voltage sense" pin is connected to the positive side of the diode bridge/output stud via a 2.5kohm resistor. So somehow I would need to control the field via a positive supply instead of controlling ground. Is there any output on the MS3 that is setup this way?

[jsmcortina]

It is possible to DIY the needed high-side driver - I've tested this out on the bench. I'll upload some diagrams when I get chance.

James

[ntstlgl1970]

That would be great, this is the only thing keeping me from driving my car....

Are there any fuel pump driver modules that are setup this way?

[ntstlgl1970]

I've got some tip-120 and tip-36 transistors around, so I'm ready to go with suggestions....

[jsmcortina]

See:

chrysler-alt.png

James

[ntstlgl1970]

Awesome, thank you- I will work on this today

[Matt Cramer]

Check to be sure the injector driver is not shorted to ground.

[ntstlgl1970]

Thanks Matt, I will be sure to do that

[MolsonB]

Not to step on this thread, do we have a collection of data yet on setting up different alternators? I have a Mazda RX8 and can barely find much info on it. Other then the attached picture and that it is PWM controlled.

I'm not ready to test yet, but hoping in a month on the bench. Guessing pin 2 would be Load Monitor input and pin 3 is the Control Output?
Side question, is there a way to deactivate the alternator via an input? If not, I guess we could put a manual switch between the PWM signal to Alt?

[jsmcortina]

That looks to be similar to the 'Miata' alternator.

James

[MolsonB]

I found one of your links on updates to the manual "MS3baseV39_Hardware-1.4-2015-12-13-chevy-alt". The top part is cut-off which I think deals with Mazda Power/Drive (PD) alternators.

When selecting 'High-speed feedback field control", the Load Monitor input gets grayed out. Wondering how does it figure out the Load %. It looks like pin D should be connected to nothing. Would it be correct to say Power is Lamp, and Drive is Field ?

Would there be any demand to add an input switch to turn Alternator On / Off? In my application, it would benefit me. Worst case, I could put a relay in-between the Lamp wire & alt.

Mazda RX8 (N3H1)
Pin 2 = D = empty
Pin 3 = P = PT4 (0-5v)

[ntstlgl1970]

Ok, after a long stretch, I'm back to sorting out this charging problem. I've got the high side driver all setup, but the output from the TIP125 is only around 3VDC so it still doesn't charge. If I ground the wire coming from the transistor that goes to the inj#1 wire on the MS3, i get battery voltage on the output like I would expect. I've tried both inj#1 and inj#2 with the same results and neither output is shorted to ground.

using the high side driver, do I still use high speed feedback or closed loop field control or ????

[ntstlgl1970]

I ended up trying a bunch of different settings and then had the high side driver transistor fail. Replaced the transistor and have the system running with the alternator being controlled correctly.I used the high speed feedback function to control the alternator. the field control follows the requested charge voltage as it should.

Thanks to James for info on the high side driver.