I remember when I wired in the PCIII to my S2R800, I had a similar situation, would prime, but no crank. Turned out I had connected a ground improperly I should have been grounded to the ECU, but I had grounded it to the neg battery terminal. Might wanna check that.

Grounded to the ECU? I thought that ground was common throughout the whole bike?  So does that make it a kind of switched ground?

Ok so here's what happened today at the workshop.....

With the knowledge and inspiration from you guys yesterday I went back with a fresh mind and a new set of eyes, I checked and re check every possible connection. I even put the kick stand switch back on and disconnected the bypass, neutral light was connected in the back of the engine all along, I pulled it out and reconnected it anyway. I studied the whole loom and made sure everything was going to the right place and correctly grounded and so on.

I hot wired the barrel and the pump primed and the relay flicked to life as before, the run switch was set to on so I went ahead and press the start button........ Nothing! Bloody nothing!!! But this time I heard a small click from the relay that I've never heard before so just to check that it was a result of me pressing the switch and not the relay timing out I did the whole process again and it flicked again. I thought I had wired something wrong and crossed polarity somewhere and shat myself thinking I was burning stuff out! But for some reason I tried taking a plug out and earthed it to the frame again as before and hot wired the solenoid. It cranked and there was a spark!!!!

Shoved it back into the engine and hot wired the solenoid again the thing cranked and started to cough and back fire so I swapped the ignition modules around cranked her again and she revved into life!!! After two years of silence I get to hear that sweat noise again! But as soon as that happened it started to dump all of the oil out from around the base of the top cylinder well at least that is where I think it came from, so I had to shut it off to the sound of my ears ringing and adrenaline pumping though me.

What a day, I'm so happy that issue is resolved thank you so much guys I was very ready to give up on it!

So it turns out that for some strange reason the starter button won't tell the ECU to go ahead with activating the solenoid?

Quote from: Willthedub on December 22, 2015, 02:56:24 PM
~~~SNIP~~~

So it turns out that for some strange reason the starter button won't tell the ECU to go ahead with activating the solenoid?

I've seen that circuit of the ECU fail on two bikes, from water getting into the instrument cluster.
Both times it also fried the wiring going down to the sidestand switch.

You can wire directly from the starter button to the solenoid, but you will lose the safety 'interlock' that the ECU provides via the sidestand/clutch/neutral sensing.

Quote from: Speeddog on December 22, 2015, 03:17:07 PM
I've seen that circuit of the ECU fail on two bikes, from water getting into the instrument cluster.
Both times it also fried the wiring going down to the sidestand switch.

You can wire directly from the starter button to the solenoid, but you will lose the safety 'interlock' that the ECU provides via the sidestand/clutch/neutral sensing.

I bet he doesn't care....

Quote from: Willthedub on December 22, 2015, 02:24:27 PM
Grounded to the ECU? I thought that ground was common throughout the whole bike?  So does that make it a kind of switched ground?

There was a ground wire that was attached to the ECU. When I disconnected the battery to work on the bike, I took that all off, but had forgotten that it was grounded there and not to the negative terminal. Had nothing to do with the PCIII.

Quote from: NAKID on December 22, 2015, 03:44:50 PM
There was a ground wire that was attached to the ECU. When I disconnected the battery to work on the bike, I took that all off, but had forgotten that it was grounded there and not to the negative terminal. Had nothing to do with the PCIII.

Oh yes, I know the one!

Quote from: Speeddog on December 22, 2015, 03:17:07 PM
I've seen that circuit of the ECU fail on two bikes, from water getting into the instrument cluster.
Both times it also fried the wiring going down to the sidestand switch.

You can wire directly from the starter button to the solenoid, but you will lose the safety 'interlock' that the ECU provides via the sidestand/clutch/neutral sensing.

Thanks speeddog! I'm trying to cut down the size of harness so this is a good tip, I'll give it a go! Side stand hitting here I come!