International 9400i ignition switch not starting

My 2006 9400i with a Cat C13 and an Eaton Ulrashift automatic 10spd decided to not start anymore. Breakers all appear to be good. Relays for ignition and start enable swapped with other working relays. No power to the solonoid on the passenger side firewall on either small posts when attempting to crank. With key in on position, engine starts when power is jumped from battery wire to start post on the solonoid (not across solonoid, so solonoid is functioning), and truck appears to function normally.

There is no change if the brake is applied or not, or if parking brake is on or not. Transmission was in nuetral. Truck always started with me standing outside previously, so presumably has no interlocks on on the brake switch. I am assuming I'm hunting for a break in the wire from the switch to the solonoid, or a bad switch.

So, does anyone know what color wire or what clock position on the back of the switch is the solonoid's trigger wire? I need to check for power output there next. I assume there is just one power input to the switch, right?

Thanks to any and all!

Fred

 

Howdy, HeavyD;

So, the pink wire is the switched wire, the TCU provides 12v to switch the relay? Since I heard the relay trip upon reinsertion, it's safe to say that the TCU gave a go-ahead for launch and the problem is then with my ignition switch or wires. Check 12v output from switch, if good check continuity to relay socket, then from socket to solonoid? Alternatly jumper 12v to relay socket to light up the solonoid; that checks that half of the circuit and gets my motor runnin'.

In the future if I have TCU issues I could remive the relay and jumper the 17a circuit, then. Not bright, but a quick redneck fix. Thoughts?

Thanks,

Fred

 

Sounds good. It self healed this afternoon, so I'm betting carbon fouling our a squished bug in the switch. I am hoping upon removal that I can take it apart and repair it instead of replacing it, if that is indeed the problem.

Thanks for the help, sir!