case 750 crawler 24v no start

Went out today to start my old case 750 and the
solenoid behind the dash will just click. Batteries
and cables were about shot so I put new ends on the
cables and installed 2 new 12v batteries....still
just have a clicking solenoid. I know nothing about
a 24v system. Old girl had been starting good
until now. Any advice would be greatly appreciated.

The only difference between the 24 and 12 volt system is the higher voltage and the way the batteries are hooked up,the batteries are connected in series,main cable positive,negative to positive on other battery,negative to ground,have you checked any circuit breaker has not popped out and check any fuses it may have,the clicking you hear is the relay solenoid for the starter,you need to look at the solenoid on the starter,you will see the heavy main cable attached to the terminal,under that there is two lighter cables attached to the solenoid,those two wires are for exciting the solenoid,when you hit start the solenoid under the dash closes and sends power down to the starter solenoid,that should close and the engine should crank over and start,one of the wires is ground,put a test lamp on the other,it should light when you hit start,if not there is an issue with the relay solenoid or the wire going or coming from it,to test the starter bypassing the wiring,make sure its out of gear and the brake on,use a jumper wire from the main cable to the terminal on the solenoid that has the wire coming from the relay.
AJ

I don't know if you have solved your problem but I have recently bought a 750 and have had the same issue. I had to replace the ignition switch. The old switch had a broken off key and was, well, old and corroded inside and therefore not conducting enough power. I would also want to make sure that your ground wire is tight and since mine is a positive ground I'd assume yours is too. I had removed a side cover and then forgot to put a bolt through the ground and had the same clicking and thought WTF? Once I had the bolt in and tight it fired right up but I had the problem again later and traced the circuit. The starter motor power goes through the switch. I'd also suspect the starter button if that doesn't work. They're relatively cheap and more or less easy to change out. I have reworked my entire starter and charging wiring. Saves headaches when you really need the machine. I used the Taylor compression-type cable ends for a size 2 cable. (Make sure yours is a 2 before ordering) IMO well worth the extra 15 bucks. This thing just spins like a top when you hit the starter button. I have had no issues with starting since doing those things. Good luck.