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Discussion Starter #1
hi,
does anyone can help me with a question regarding the ignition control module please. it's about the pink wire that it is present for the 98-99 models but doesn't show up on 96-97 models. what's the purpose of that wire ?? i tried to measure any voltage on that wire but with the ignition ON but nothing?! why i'm asking? i've swapped a 99 engine on my 97 fireblade and fires up and runs good with the old ICM but when i've swapped the 99 ICM too i doesn't start up anymore..and the only wiring difference is the pink wire...
thank you
 

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If it's the same as the 929/954 I think it's to the ignition diode.
Have you got a '98/'99 igntion switch you can try?
You would have to run a wire from the connector to the ECU of course to do the job of the missing pink wire.
I'm surprised both ECU's plug into the same connectors.
 

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Discussion Starter #3
i'll try that...thanks
...what's the role of that diode??... can i "simulate" it tot the old switch so i don't have to run wires?
 

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i'll try that...thanks
...what's the role of that diode??... can i "simulate" it tot the old switch so i don't have to run wires?
As I said, first you need to confirm that's what it's for.
I have no idea what its purpose is. I think the diode is designed to protect a circuit so perhaps it prevents damage to the ECU in some way - just a very wild guess :)
I believe it is possible to solder a diode into the wire but I don't know the details.
Why do you want to run the '99 ECU?
 

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hi,
does anyone can help me with a question regarding the ignition control module please. it's about the pink wire that it is present for the 98-99 models but doesn't show up on 96-97 models. what's the purpose of that wire ?? i tried to measure any voltage on that wire but with the ignition ON but nothing?! why i'm asking? i've swapped a 99 engine on my 97 fireblade and fires up and runs good with the old ICM but when i've swapped the 99 ICM too i doesn't start up anymore..and the only wiring difference is the pink wire...
thank you
Well it ties into the ignition switch to something called VC. The BATT, FAN and IG wires are the only ones shared with the 96-97. Well since the BATT looks to be incoming, the FAN and IG are outgoing and you picked up no voltage with the key on, it would stand to reason that VC is outgoing too.You need to be careful with that circuit since it feeds directly to the ICM, send too much voltage and you will probably kill it.

After comparing the differences in the bikes, it looks like you have nothing to gain by using the 99 ICM. The power outputs are the same and although the weights are 5kg difference, since they are both carbed, no air/fuel maps to be set to that weight.

Honda-Fireblades.co.uk - Fireblade History.

If it had been a fuel injected engine then yeah you would need to worry about that circuit, but as it stands, I would just plug the 97 ICM in and ride it.
 

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As I said, first you need to confirm that's what it's for.
I have no idea what its purpose is. I think the diode is designed to protect a circuit so perhaps it prevents damage to the ECU in some way - just a very wild guess :)
I believe it is possible to solder a diode into the wire but I don't know the details.
Why do you want to run the '99 ECU?
Yeah i think you hit the nail on the head Blade:rotfl:(inside joke)

I do believe it is a diode wired in to reduce the charging voltage to signal something to the ICM. But I was unable to figure out why looking at the diagram.
 
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