Bench top Engine Simulator for the P01/P59 Pcm

[Gampy]

[edit]
My apologies, I wrote the voltage and resistors wrong ...

The Injector LED hookup is, Cathode to Injector Signal, Anode to +5v thru a 200 Ohm resistor. (Red, Black, Brown, Gold)

So, Correctly,
The Injector LED hookup is, Cathode to Injector Signal, Anode to +12v thru a 100 Ohm resistor. (Brown, Black, Brown, Gold)

As soon as the Pcm gets +B the led glows dim, turn ignition on, it dims a bit more.

When it gets a signal it does go full bright ... However it always remains dimly lit.

Would that indicate a pullup/dn resistor is needed?

Thanks

[MudDuck514]

Gampy,

Measure the voltage from the PCM side to ground, and ACROSS the resistor. Also, if you can, measure the LED current while on and off. Let us know the findings please.

What you may want to try is increasing the value of the resistor to 1,000 ohms. (Brown, Black, Red, ?)

There is a small leakage current through most transistors, and the 200 ohms may be too small to make the LED turn off completely.

Mike.

[Gampy]

Gampy,

Measure the voltage from the PCM side to ground, and ACROSS the resistor. Also, if you can, measure the LED current while on and off. Let us know the findings please.

What you may want to try is increasing the value of the resistor to 1,000 ohms. (Brown, Black, Red, ?)

There is a small leakage current through most transistors, and the 200 ohms may be too small to make the LED turn off completely.

Mike.

First off, note my edit above changing values.

Flying a bit high for me bud ...
Across the resistor??
Measure LED current??

The Injector signal is to ground, so ground to ground??
So I unhooked the Injector signal and hooked it to the black lead on the VM, the VM red lead to +12v and this is what I get:

20191215_133240.jpg (150.99 KiB) Viewed 3552 times

7.70v.
With the LED still hooked up: 2.49v
And for reference I get 13.17v on the Battery.

[edit]
I think I did wrong, if I put the VM red lead on the Signal wire, VM black to ground, while the signal wire is hooked to the LED I get: 10.84v.

[DavidBraley]

I love that vintage Radio Shack multi-meter!

[Gampy]

Love my old RS analog, so simple ... So many good years, still my #1 go to for basics.

However, I suppose I should fess up ... I ain't 2 digit good at reading an Analog meter!

20191215_133051.jpg (107.85 KiB) Viewed 3526 times

[MudDuck514]

First off, note my edit above changing values.

Flying a bit high for me bud ... [no worries, I find this easy ONLY because I have been an Electronics Tech for over 35 years!]
Across the resistor?? [Yes, we want to know how much voltage the resistor is "Dropping"]
Measure LED current?? [Don't worry about it. We can calculate the value.]

The Injector signal is to ground, so ground to ground?? [Technically the injector signal is PULLED to ground and not always AT ground, but YES.]
So I unhooked the Injector signal and hooked it to the black lead on the VM, the VM red lead to +12v and this is what I get: [You need to leave everything hooked up as it normally is]

20191215_133240.jpg

7.70v.
With the LED still hooked up: 2.49v [How is the meter connected? Red to Batt and Black to PCM?]
And for reference I get 13.17v on the Battery.

[edit]
I think I did wrong, if I put the VM red lead on the Signal wire, VM black to ground, while the signal wire is hooked to the LED I get: 10.84v. [THIS is what we actually WANT. It means the LED AND Resistor are "Dropping" the rest of the voltage - only problem, MOST is across the LED. ]

Gampy,
See my notes in the Quoted text.

To Calculate the correct size resistor, we need the LED voltage (Vfd) and the required current for proper operation. BOTH of these specifications are in the data sheet for the LED.
If you can find the information, let me know and I'll walk you through the rest.
Otherwise, try using a 1k to 2.2k Ohm resister in place of the 100 Ohm you have.

Mike

[Gampy]

Leaving everything hooked up.

Yes, the 2.49v is with VM Red to +12v and VM Black to PCM.

Across the resistor is 4.8v.
I think I just learned something ... Just to make sure Ive done this right, I connected VM Red to one side of the resistor, VM Black to the other side. while it's powered and it showed how much voltage it drops??
Never done that, just Ohm'd them unhooked because I didn't know how to read the color codes. I do now.

The LED's are an assortment of 10 pieces each of 6 colors off Amazon they came with resistors, a color dot is the highlight of information ...

I have lots of resistors, I doubt I have enough of the same value other then what came with the LEDs, I can order whats needed in the end.

[Gampy]

Just dug out these leftovers, Cree, Inc. Water Clear Cool White LEDs.

I am completely self taught through many decades of, I try, I make smoke, I try something different ... I know very little about electronics 'proper' and I didn't start muddling in electronics until later in life.

And I can't see them little buggers running around to understand what they are doing to confirm thoughts either!

[pman92]

Put a pull up resistor on the PCM side of your LED and it will stop it glowing dimly

[Gampy]

Pullup is to Power??
What size resistor??

[edit]
Ok, I looked it up, Pullup is to power, this scares the shit out of me, putting power to a ground ... I don't get it!

You are way smarter then I with this shit, so I dove in with faith, with a 22kOhms 5% (Red, Red, Orange, Gold) and it worked!

I only left it hooked for a quick nano in case I'm doing bad with resistor choice, I have no idea how to calculate a proper resistor.