Question about Welding Tools
Cant find alternator
Most engine driven welders have the charge armature located underneath the flywheel of the engine, but you need to check a couple of other things before you start tearing down the engine. Look for a small rectangular module on the blower housing of the engine, on a Kohler this is at the side, on an Onan it's at the top. This is the rectifier/charger module and it will have 3 wires, the 2 on the outside will be the AC from the armature, and the middle one is the battery charge positive. With the engine not running, use a DC voltmeter to measure the voltage between this middle tab and the engine block, you should see a voltage that's very nearly equal to the battery voltage. If you don't see a voltage there you may have either a blown fuse, a tripped circuit breaker, or a broken wire leading to the battery. On some welders the fuse or circut breaker is inside the welder cabinet on the bulkhead between the engine and the generator parts of the welder.
If you did see battery voltage at the charge terminal, start the engine, switch the voltmeter to measure AC voltage and measaure the voltage from one of the outside terminals to the other, you should see 15 volts or more (be careful not to short out anything). If you get a nice AC voltage, switch back to DC and measure the charge output again (engine block to middle tab), it should be greater than the battery voltage we measured before and it should be slowly getting greater, if not the rectifier/charger module is bad.
If you didn't see enough AC going into the module, stop the engine, disconnect the plug from the module and use an ohm meter to measure the resistance between the 2 outside wires that go back to the engine, something between 100 and 1500 ohms is good. If you measure an open circiut (OL on my meter) or if you measure 0 ohms, the armature is probably bad. You have to take the flywheel off the engine to see the armature. If you got a good restance reading but the voltage is still low you may have one or more broken magnets inside the flywheel, again you have to do some serious disassembly to see if that's the case.
Posted on Nov 29, 2008
There is no Alternator. The welder is a big generator. The welder uses the battery for stored energy to start the engine which in turn spends the generator. By use of a voltage regulator the 115 volt plugs on the welder work and the battery is recharged. If you find that the welder will not start and the toggle switch wiil not work properly, its probably the voltage regulator. Check the battery first, then move on to the regulator. Chasing parts start with Kohler or with the engine type you may have. Get the model number and serial number off of the fly wheel cover. Good Luck
Posted on Feb 16, 2013
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Posted on Jan 02, 2017
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