I have a cat 242b that I cannot seem to get to charge. I sent the alternator out to have it checked and it is was bad. I replaced it with new and the machine still will not charge. I took the new alternator off and had it tested and it is good. Where do I start to trouble shoot this I am also having problems with the hour meter not working. Can they be related issues?
Maybe the battery is bad?
Just thinking out loud, did you happen to check for a blown circuit breaker? Should be a red or blue button in the cab or in the engine compartment. Where are you checking for voltage or how do you know it's not charging? I'm guessing the machine starts and runs? Looks like breaker is in engine compartment: That would be a good place to start anyway.
The machine will start and run but the idoit light is on and when I check the voltage at the battery while the engine is running the voltage is not 13 or 14 like it should be.
I am currently running into the exact same problem with my Cat 242b. I have not replaced my alternator yet but from my readings with my multimeter it is not jumping up to 14v when the engine is idling at 2000rpm, yet just staying at 12.5v. D9gdon, could you explain the blue 105 circuit breaker that you talked about? I can press it in, but how do i tell if it is "tripped" or bad. Secondly where did you get that diagram? I am trying to make sure it isn't something simple before i reman my alternator. Thank you for any information that you can provide. onemoreparnut, Did you get your problem resolved with the alternator and with the hour meter? thanks
Hi Veb2127, you haven't posted a serial number and there are quite a few differences between models so I will take a guess with this info here is a break down of elec sch for your machine (guess only ) you should have power at D+ terminal to excite alternator. if not you need to track back through wiring. the circuit is as follows, power from ignition switch is supplied to resistor p/n 2389397 and then to blocking diode p/n 1068704 and then to D+ terminal on alternator. wire no 403 goes to your hr meter hope this helps
2004 Cat 242b BXM00505
That drawing is from the parts book. That circuit breaker just protects the system like a thermal overload. If it's blown, it'll click when you reset it and you can feel it too. Just check the voltage going in and coming out if you're not sure. Sounds like your alternator is bad. Take it off and have it load tested at your auto parts store.
Thank you Mark 250 and d9gdon. I'll update with results for other peoples knowledge in the future.