85 GL1200 Aspencade - No spark

[EirikS]

Hi all,

New member from Norway here.

I've purchased an 85' GL1200 Aspen in pieces and during reassembly im not able to get any spark. I've tested ignition, cleaned killswitch, tested ICM on another bike (fired right up) tested ohms on PG and resistance-tested the coils. My main concern is that i'm getting a constant 12v to the coil leads, no pulse just the constant 12v as soon as the ignition is on and even when trying to start. I've grounded the ICM and coil to the battery as well, but some of the wiring is not connected yet (oil sensor, fan, the main shroud with dash). Could the PGs cause the ICM to provide coils with un-interupted 12v even when starting? or could it be due to a issue with the wiring/ground/missing connection somewhere?

Brgrds
Eirik

[WingAdmin]

Hi all,

New member from Norway here.

I've purchased an 85' GL1200 Aspen in pieces and during reassembly im not able to get any spark. I've tested ignition, cleaned killswitch, tested ICM on another bike (fired right up) tested ohms on PG and resistance-tested the coils. My main concern is that i'm getting a constant 12v to the coil leads, no pulse just the constant 12v as soon as the ignition is on and even when trying to start. I've grounded the ICM and coil to the battery as well, but some of the wiring is not connected yet (oil sensor, fan, the main shroud with dash). Could the PGs cause the ICM to provide coils with un-interupted 12v even when starting? or could it be due to a issue with the wiring/ground/missing connection somewhere?

Brgrds
Eirik

That's how it works - there is a constant +12v supplied to one side of the coil, and then the ECU switches the ground on and off for the other side when it wants it to spark.

[EirikS]

Hi all,

New member from Norway here.

I've purchased an 85' GL1200 Aspen in pieces and during reassembly im not able to get any spark. I've tested ignition, cleaned killswitch, tested ICM on another bike (fired right up) tested ohms on PG and resistance-tested the coils. My main concern is that i'm getting a constant 12v to the coil leads, no pulse just the constant 12v as soon as the ignition is on and even when trying to start. I've grounded the ICM and coil to the battery as well, but some of the wiring is not connected yet (oil sensor, fan, the main shroud with dash). Could the PGs cause the ICM to provide coils with un-interupted 12v even when starting? or could it be due to a issue with the wiring/ground/missing connection somewhere?

Brgrds
Eirik

That's how it works - there is a constant +12v supplied to one side of the coil, and then the ECU switches the ground on and off for the other side when it wants it to spark.

Have i got it wrong then? Is it the PG who «decides» when the ground switches and the coil fires? Is there any other way to meassure the PG than resistance? I tried a AA battery to «trigger» spark signal, but no luck.

[WingAdmin]

Hi all,

New member from Norway here.

I've purchased an 85' GL1200 Aspen in pieces and during reassembly im not able to get any spark. I've tested ignition, cleaned killswitch, tested ICM on another bike (fired right up) tested ohms on PG and resistance-tested the coils. My main concern is that i'm getting a constant 12v to the coil leads, no pulse just the constant 12v as soon as the ignition is on and even when trying to start. I've grounded the ICM and coil to the battery as well, but some of the wiring is not connected yet (oil sensor, fan, the main shroud with dash). Could the PGs cause the ICM to provide coils with un-interupted 12v even when starting? or could it be due to a issue with the wiring/ground/missing connection somewhere?

Brgrds
Eirik

That's how it works - there is a constant +12v supplied to one side of the coil, and then the ECU switches the ground on and off for the other side when it wants it to spark.

Have i got it wrong then? Is it the PG who «decides» when the ground switches and the coil fires? Is there any other way to meassure the PG than resistance? I tried a AA battery to «trigger» spark signal, but no luck.

The coils are supplied +12V through the kill switch on the handlebars, to one of the primary terminals on both coils.

The other primary terminal on each coil then goes to the ignition coil module. This module has transistors in it that pulses a connection to ground at the appropriate time. The pulse generators send pulses based on the engine rotation to the ignition coil unit to trigger the transistors so that it creates spark at the correct part in the cycle.

If you have the ignition turned on and connect the second primary terminal (not the one connected to +12V - so the yellow/green or blue/yellow wires) to ground momentarily, you should be seeing a spark.

If you connect a scope to those yellow/green and blue/yellow wires when the engine is cranking, you should be seeing pulses to ground (referenced to +12v).