BIP373 - Coil ALWAYS Powered (SOLVED)

[efims]

Pin 7(right of R25) and Pin 8(Right of R28) of U1 (MS1 V2.2) with 330Ohm to BIP373 (left)

Center BIP373 to coil, Right leg of BIP373 to Ground.

Somehow the Center BIP373 to coil kept going to -ve(giving 12V to Coil).

I set the Spark Output Inverted "YES"

Since it is giving power to coil(I am on Bench test and did not connect the output to a coil. I have a DMM to measure Voltage and center leg of BIP373 goes Ground at ZERO rpm), I set to "No" but still have the same 12V to coil

In short, regardless Spark Output Inverted "Yes" or "No", I still get 12V going to the coils

(Positive of coil is thru relay which also power the MS1 ECU)

Is there any other circuit that I need to add? eg Pull-up 1k to 12V+?

[dontz125]

A pull-up to +12v won't help anything.

How do you have it mounted? Do you have a Mica insulator between the case and the tab? Check for burrs in the drilling; burrs can poke up through the insulator and ground out the tab.

[efims]

Dontz125,

1. Since I am bench test, the BIP373 is left floating(not mounted to anything). I am aware that the TAB has to be well insulated to avoid shorting to the Ground.

2. I edited me my initial post...the output(center Leg of BIP373) is measure thru DMM..will this be different if I were to connect to an ignition coil?

[dontz125]

I just re-read your post, and one of us is missing something - assuming this is a TCI / Kettering ignition, the coil is SUPPOSED to be always powered. Your description is quite confusing.

If you don't have a coil to hand, then yes - a pull-up to 12v at the collecter should show whether the device is working. I've seen many comments about how the high impedance of DMMs can cause bizarre readings when testing for voltage if the circuit isn't actually working.

[efims]

To add, From U1 with 330Ohm to DB37 of MS ECU, I have Jimstim connected

I2B to the test LED...the LED is illuminated (at ZERO RPM) while LED on MS Board D15 and D16 are not illuminated. Is this normal?

[DaveEFI]

Dontz125,

1. Since I am bench test, the BIP373 is left floating(not mounted to anything). I am aware that the TAB has to be well insulated to avoid shorting to the Ground.

2. I edited me my initial post...the output(center Leg of BIP373) is measure thru DMM..will this be different if I were to connect to an ignition coil?

Measuring the output of any solid state switching device which isn't connected to its load is pointless. It may well conduct enough to give a reading on a high impedance DVM. If you don't have a coil to hand, connect a suitable 12v bulb to act as a load. Something like a 5watt 12v one will be fine.

[efims]

Thanks for comments.

I will try it on the car first thing tomorrow

[jsmcortina]

Before connecting to your ignition coil, connect up a 12V bulb in its place. If the bulb lights up, that's wrong...

James

[efims]

THANKS

Managed to put a load(relay) and it worked as expected.

No Ground supply from BIP373 to the relay at ZERO rpm.

DMM is not suitable for this procedure

[DaveEFI]

THANKS

Managed to put a load(relay) and it worked as expected.

No Ground supply from BIP373 to the relay at ZERO rpm.

DMM is not suitable for this procedure

It is. Nothing wrong with the DVM - just the procedure for using it. Anything used to measure voltage should draw as little current as possible, otherwise it could give an inaccurate reading. But this also means to will give a reading of sorts on 'stray' currents.

[billr]

You don't even have to go to the bother of finding a light or such to put a "real" load on the device. Just a little resistor, anything up to 100K, would have been good enough of a load to get a true reading with DVM.

[DaveEFI]

You don't even have to go to the bother of finding a light or such to put a "real" load on the device. Just a little resistor, anything up to 100K, would have been good enough of a load to get a true reading with DVM.

Yes. I mentioned a bulb because it's something most will have lying around.

[efims]

THANKS GUYS

Yes, a bulb or resistor across the output will give the true reading on DVM(or DMM in voltage)

I manage to run the ECU with Spark Output Inverted YES.