2007 9400i not cranking

VIN: 7C532829

I've replaced the ignition switch already, because I wanted my door locks and ignition switch to match. Already swapped relays in the glove box. Replaced starter solenoid on the firewall.

What would happen before, is every now and then it would just click really fast when I turn the key. If I shut off my blower motor, it would crank. Like it wasn't getting enough voltage or something. But recently, you turn the key, and nothing. You could hear the relay in the glovebox click, but that's it. So I used a claw hammer to short the lugs on the firewall solenoid, and the engine cranked over perfectly. That led me to believe that solenoid was bad. I verified yesterday the truck would still not crank before I replaced the solenoid. So I went ahead and put a new one on. Cleaned all wires with emery cloth. Also cleaned 150 amp fuse and ground lug. Truck cranked over perfectly with key. Problem solved...

Got in it this morning, no crank. Had to short the solenoid with a hammer again. WTF am I missing? What else is in between the key and that solenoid?

 

After it warmed up, I killed it and restarted with the key five times in a row. It was 27 degrees this morning. Not sure if that adds to the puzzle or not. But shorting the firewall solenoid causes it to crank no problem at all. No drag, engine cranks quickly and fires right up.

 

International with a 10-speed, and it doesn't require the clutch pushed in to start it. I've also recently removed all the battery cables and shined everything up.

It's really stupid and intermittent. Sometimes it fires right up. Sometimes it clicks really fast, and then fires. Sometimes it doesn't do anything, and I have to short the solenoid on the firewall to get it to crank. So it's definitely got the juice to crank, but I think it's got to be something between the key switch and that solenoid on the firewall. But I'm not 100% sure of the circuit. I think it's: key switch>relay behind glove box>firewall solenoid>starter solenoid. Is there anything else that affects that circuit?

 

No. If I short the firewall solenoid, they have no trouble winging the engine over.

I don't think it could be that. If it were, then it wouldn't crank even when I short the solenoid on the firewall, correct? I'd need to energize the bendix and bar the engine to move off the flat spot before it cranked at all I'd think.

 

I mean it's worth a shot, right? I could just jumper the switch and see next time it doesn't want to start. I know the switch at least can work, because it will kill the Jakes and the cruise.

 

LOL, honestly it's because I'm always bothering that guy. I figured this time I'd let him get around to it whenever. In the meantime, I've always got a hammer!

This solenoid has the regular two large lugs, and then two small lugs. I've never tried to key it on while checking with a multimeter, because I've been by myself and I can't reach. Thing is, I've got jumpers I could rig, but it was so dang cold this morning, and I was pissed that I hadn't actually fixed it, that it completely slipped my mind. So I'm not actually sure if the solenoid is even getting signal during the times it won't crank.