This has been discussed, and I have reviewed older threads, but thought it worth asking my question in a new thread to see if there might be specific thoughts on solving my no-crank issue. I recently had the apparently common issue on my 1845c where I turn the ignition key and there is a single click but no crank. My battery is good and connections clean and tight. I read about and purchased an external solenoid kit and installed it. Now when I turn the key I get louder, rapid clicks, similar to a dead battery. Putting a charger on the battery or directly to the starter solenoid doesn't change anything. From earlier comments it sounds like maybe my next best step is the ignition switch? Any other thoughts? Here is the relay:
All three (4 if you count the one I sold) had that issue. The 3 molded plugs that allow the harness to be disconnected when sliding the cab forward lose the ability to pass full current, either due to tension loss or corrosion. I lopped them off and replaced them with deutsche connectors. If nothing else, have someone fiddle with them while holding the key in the crank position.