Bill Birmingham

For anyone who might buy that box and has a 3d printer, I whipped out this design tonight to mount the box.

https://www.thingiverse.com/thing:4403473

LSswap

I don't know about that 12V switched ignition. That's going to generate a 12V PWM. I don't know if the alternator's regulator is going to like that for a long time, I was under the impression it's used to seeing a 5V PWM. I'd feel more comfortable if you hooked the Vin+ to a 5V source...That will give you a 5V PWM.

Nice!

Bill Birmingham

If you look at the product I linked, you can set the output voltage from 0.1V to 12.0V. I set the output to 5V as you originally instructed.

robjust

Bill, I do not have a 3d printer, but would gladly pay if you would consider printing a box out for me. Thanks for sharing, and all the help !

LSswap

Very cool. The one I had only put out whatever voltage you supplied.

Bill Birmingham

Rob;

Send me a message. It takes a little over 3 hours to print one from PETG... I charge $3.00/hr for 3d printing + shipping. So $10+ship.

robjust

Bill, Not sure I can message you yet, I tried, and it says I do not have permission to do that yet? More then happy to pay you for your time / shipping. It would really make it a nicer / tidy install. If you want you can email me at robjust@gmail.com or if there is another way that I am not seeing, please let me know. I also tried to message you thru your iTrader and I get the same message. Thanks in advance, and I appreciate all you and LSswap do sharing your knowledge and expertise.

Bill Birmingham

Well, I'm a n00b here too... Will send email shortly.

Bill Birmingham

Here's a photo of the fitment into the box. It just pushes in, and friction holds it in place.

wicked_95z

iTrader: (8)

Im still getting my *** kicked with this one. Am I screwing up by using a 5v reference and ground from a holley sensor and not from the e40 PCM by chance?

Project GatTagO

iTrader: (7)

What exactly are you trying to do? Are you using Holley EFI?

Andrew

wicked_95z

iTrader: (8)

No, sir, I'm only using one of the holley sensors for the 5v and ground to power the PWM signal generator that LSwap posted. I've also tried just using the 5v from the sensor and engine ground to power the generator.

I've tried every combination of attaching and disconnecting and providing the signal to the alternator I can come up with for the two wires to the alternator. It either doesn't charge or on charges to 13.5vdc at the master disconnect switch (holley only read 13.0-13.2). I've had the alternator checked at two O-riley's and they both got over 14vdc out of it.

LSswap

So at is point we need to stop guessing and get some real information. You remember that little scope thing at the beginning of the post? That is the best way to figure out what the signal going to the L terminal looks like. Maybe your pwm generator is broken, maybe there is something else attached to the L terminal. Lots of maybes but no real info.

A voltmeter on the L terminal won't give you as much information, but it may still be useful. An old anolog voltmeter might be better than a digital one. Try putting a voltmeter on the L terminal and measure the voltage as you change the PWM duty cycle and let us know what the voltage you see for each duty cycle. Also make sure you're really on the L terminal and nothing else is attached to that terminal other than the PWM generator. The voltage should roughly go up and down between 0 and 5 volts as you increase and decrease the PWM duty cycle.

If you get no voltage change, then next step is to take the alternator out of the equation. Disconnect the PWM out from the L terminal and connect the PWM out only to the voltmeter and try the PWM duty up and down again. It should show roughly 0 to 5 volts on your meter. If it doesn't change then you burnt out the PWM generator transistor.

BTW, if you attached the PWM output of the PWM generator to some 12V source, by accident, somewhere along the way, there's a good chance the output transistor is burnt out. If you had the PWM generator attached to the L terminal while the L terminal was still attached to ECM, then that may possibly have burnt it out.

Let's stop guessing.

Bill Birmingham

For the money, this isn't a bad scope... I was actually thinking about buying one.

wicked_95z

iTrader: (8)

Yes, sir, I ordered a scope with the signal generator:
I've check the signal from the signal generator and I get a square wave at 128Hz and 5V max. I did attach the signal generator to 12vdc when the 5vdc wouldn't work but the generator does still work, as I checked the output again last night. It's been a couple of months but I'm pretty sure I didn't try 12 vdc with the alternator attached to the ECM.

An important thing on my setup that doesn't match what you have posted is, according to the schematic for the GTO, the L terminal on the alternator is attached to the ECM's "generator turn on" pin and the F terminal is attached to the "Duty Cycle Sig" pin. But I've tried the signal generator, on 5vdc, to both wires with the 2nd wire connected and disconnected.

~~~~~
EDIT: Disregard above about the L and F terminal. I misunderstood based on the naming of the signals and forgot you mentioned that both wires have a DC signal: one from the PCM and one to the PCM

From the diagnostic information:

L Terminal: The ECM uses the generator turn on signal circuit to control the load of the generator on the engine. A high side driver in the ECM applies a voltage to the voltage regulator, signaling the regulator to turn on and off.

F Terminal: The ECM uses the generator field duty cycle signal to monitor the duty cycle of the generator. The ECM monitors the stat of the generator field duty cycle signal circuit. When the engine is running, the duty cycle should be between 5-100%

LSswap

I'm still a little confused as to why you want to use the PWM generator when you have the correct ECM, but despite that, let's try to get you going.

Rule 1) At any time, only one of the two controls, ECM or PWM generator can be physically connected to the alternator terminal L.
Rule 2) We are only concerned with terminal L. Double check the diagram and make sure you're actually on terminal L. Don't trust the color.
Rule 3) the scope and the PWM generator should use a good chassis ground to exclude any possible grounding issue with your other wiring.
Rule 4) The PWM generator should be supplied by 5V only (unless you have one like the one posted recently that can have the output adjusted to 5V)

What signal do you see on terminal L with the ECM attached?
What signal do you see on terminal L with the PWM generator attached?

LSswap

Doesn't look bad. 200Khz bandwidth may be good enough for most things. Big difference between that one and the one I got is that one needs a power source. Mine has an internal rechargeable lithium battery and a 20Mhz bandwidth.

Bill Birmingham

Have a link to it? I thought you modded an old Apple Ipod. lol

LSswap

If you want to make Jeff richer or look up DSO168. I got mine on ebay for $40.

Sway Tale

Does anyone know if the controller with **** can vary output voltage, I haven't had a chance to install this yet.