Your 450 should already have an ammeter in the dash. If its working you should see it move up into the plus side when the engine is first started. It will slowly then creep back to zero as the battery charges. If you hook up jumper cables to the crawler's battery, with the engine stopped, and you notice the ammeter dipping down in the negative range, you've got something drawing current when it should not. The older 450s have a generator/regulator combo. The newer ones have an alternator. Your crawler may have originally had a generator and been retofitted with an alternator like I did to mine. If your ammeter is broken but still connected you can do a quick and dirty test with a 12V light bulb. Disconnect the two wires running to the ammeter. Connect a 12V light bulb between the two terminals. If the bulb glows or lights then current is flowing. Problem is you don't know which direction. With the engine off and the switch off you should not have any current flowing. If you do then there is a short somewhere. Something you probably already know but its good to repeat is that a charging or discharging battery is a force to be recon'd with if you happen to create a spark anywhere near the battery. Any lead/acid battery can explode if a spark happens to occur nearby, but they are especially dangerous when they are discharging or charging because they give off more hydrogen. Just be carefull with those jumper cables cause that battery is right next to you. Best of luck, John 1968 Case 450
|