135 generator

Sdaniel

New User
As it turns out battery just needed charge. How do you test generator to know it is working? Thanks for your help.
 
Check the battery voltage with the engine stopped then start the engine and check again. It should increase while running if the generator is working correctly.
 
Couple of years ago, someone posted same question and answer. It involved grounding either the (F) field or (G) generator post. That made the generator go to full amps reading on the amp gauge if working. Please wait for the correct answer.
 
On MF with Delco generators set the engine speed about half, then ground the field terminal. Grounding the field bypasses the regulator. If the ammeter shows a charge then the generator is working but the regulator is not. If no change then the generator needs repair. Another test is to remove the generator belt and use a jumper wire, touch the battery hot terminal to the generator amp terminal. A good generator will turn like a motor, but not fast. Lots of Delcos just need cleaned and the stuck brushes freed up from sticking in the holders.
 
Grounding the field terminal bypasses the "regulator" side of the voltage regulator. If grounding the field does not show a charge you need to also check the "Cut-Out" side of the regulator. To do so, jumper from Armature on generator to BAT terminal on regulator. (Stay away from post threads on A terminal of generator as an arc can damage the threads.)

If jumpering from Armature to GEN then shows a charge the cut is bad and regulator needs to be replaced.

If jumpering Arm to Gen and grounding the Field you have completely bypassed the regulator, so then a no charge condition indicates a problem with generator, wiring, or ground connections.
 

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