GM Ign Module Wwiring

[mopowers]

Does anyone happen to know how to wire one of these later model GM ignition modules up to a MP distributor? As you can see in the second photo, there are 4 pins, so I'm assuming two go to the pickup in the distributor, whereas two go to the coil (-) and (+). Only reason I ask is that I happen to have a several of these laying around and am hoping to use one to get my 400 fired up.

 

[67Dart273]

I'm not too bloody certain that is a GM HEI module..............

Where did you get it and what is it supposed to fit?

 

[Tsully]

It’s just a different version of the 4 pin we’re used to seeing, it looks like something from the mid 80’s to early 90’s.

@RustyRatRod correct me if I’m wrong here

 

[mopowers]

I'm not too bloody certain that is a GM HEI module..............

Where did you get it and what is it supposed to fit?

It's GM. From what I've been able to find, it shows as 1995-2005. It's used in pickups, van, etc.

I was able to find this:

It says (A) is 12v, (B) is ignition signal, (C) is engine ground, and (D) in switching signal.

https://easyautodiagnostics.com/gm/4.3L-5.0L-5.7L/ignition-misfire-diagnostic-tests-2

Does that mean (A) and (D) go to the coil, and (B) and (C) go to the distributor pickup?

 

[Tsully]

It's GM. From what I've been able to find, it shows as 1995-2005. It's used in pickups, van, etc.

I was able to find this:

View attachment 1715730178

It says (A) is 12v, (B) is ignition signal, (C) is engine ground, and (D) in switching signal.

Part 2 -How to Test a Misfire / No Spark-No Start Condition (4.3L, 5.0L, 5.7L 96-04)

Does that mean (A) and (D) go to the coil, and (B) and (C) go to the distributor pickup?

That I can’t tell you, I’m used to the flat module wiring diagram,

 

[67Dart273]

Those labels don't make sense to me. The "usual" GM module and the Mopar 4 wire module hook up exactly the same, "functionally"

You have the module ground
1 terminal is coil NEG
1 terminal is BAT (ignition run) along with coil+

Other two are pickup terminals.

!!!DOH!!! Here........they have a diagram........

NOTICE THERE IS NO distributor pickup---this thing is triggered by another module. This is an EFI car so it's controlled by the engine control module, it's just that the coil driver stuff is external rather than inside the EFI module No idea what "that trigger" signal is
Edit try again........

 

[mopowers]

Those labels don't make sense to me. The "usual" GM module and the Mopar 4 wire module hook up exactly the same, "functionally"

You have the module ground
1 terminal is coil NEG
1 terminal is BAT (ignition run) along with coil+

Other two are pickup terminals.

!!!DOH!!! Here........they have a diagram........

NOTICE THERE IS NO distributor pickup---this thing is triggered by another module. This is an EFI car so it's controlled by the engine control module, it's just that the coil driver stuff is external rather than inside the EFI module No idea what "that trigger" signal is
Edit try again........

View attachment 1715730250

That diagram makes it a lot more clear to me. I was confused by the terminology. Like you said, it looks like the the white wire is triggered by a separate PCM. Not sure I can make this work with a magnetic pickup trigger. Oh well - I'll use an older style 4-pin HEI module. I appreciate the help.

 

[RustyRatRod]

It’s just a different version of the 4 pin we’re used to seeing, it looks like something from the mid 80’s to early 90’s.

@RustyRatRod correct me if I’m wrong here

Yeah it is. It's for the later small cap HEI stuff.

 

[67Dart273]

Yeah it is. It's for the later small cap HEI stuff.

Except it isn't Rob. It's not triggered by a pickup. It's driven by a signal from an ECU.

 

[pishta]

Is the signal a 5v pull up/down or a 12v ? It may be able to be triggered from a pick up only. You'd have to test it, rig it up and spin the distributor to trigger a coil to ground spark gap. Iirc the trigger from an MP distributor must be conditioned, ie amplified for anything to use it. Even an ECU can be used as an amplifier but that would be defeating the purpose.

 

[BillGrissom]

Check the megasquirt site since I recall photos and description of that "GM module integral w/ coil". It is not the "small cap" HEI module, which is the preferable one and many here use (1985-95 GM V-8 trucks). Preferable because a GM cable connects it to their "external coil", and uses sealed Weatherpack connectors. For earlier GM HEI modules, ground is via the mounting screw, but your 1996+ one uses a wire, as 67Dart273 shows in post 6. Also, you can't trigger it directly from a Mopar distributor (or even a GM distributor), since it needs a processor in-between.