My generac diesel generator is only putting out 80 volts

If you need to have new diesel generator set, maybe you can contact [email protected]

Most of the time it is the AVR that has blown. Check out our videos on how to test them.
We hold your AVR in stock and have a whole Help Center dedicated to helping people fix their Portable Generators. Check it out on our site. https://www.generatorguru.com/

Parts Spares for Generators and Small Engine Machinery

Try putting 12 volts across the commutator at the brushes. Ust a low current battery nor a car storage battery.

Good luck,

Marty

Randy, connect up your volt meter and try manually reving up the engine. Even a few hundred RPM can make a big difference in the generator output.

If that resolves the problem, then you need to adjust the high speed settings on the motor.

check voltage input at voltage regulator, then check output from
the regulator.

WAS A 110 VOLT CIRCUIT RAN TO IT FROM THE NORMAL UTILITY POWER OF HOME OR BUILDING IT FEEDS?
NORMALLY THIS IS DONE IN A SEPERATE CONDUIT FOR CONTROL WIRES.AND THE FEEDERS ARE IN ANOTHER CONDUIT.
WITH A DIGITAL TEST METER,CHECK FOR 120 VOLTS AT THE BATTERY CHARGER IN THE GENERATOR CABINET.USUALLY THERE IS A RECEPTICAL TO PLUG THE CHARGER INTO.
IF VOLTAGE IS PRESENT AT THE BATTERY CHARGER AND INDICATOR LIGHTS ARE ON, CHANGE METER TO DC AND CHECK FOR 13.8 VOLTS OUTPUT FROM THE BATTERY CHARGER.IF YOU HAVE OUTPUT VOLTAGE TO THE BATTERY,AND IT IS DEAD,CHANGE THE BATTERY..

HOPE THIS HELPS YOU,BEST OF LUCK.....

generac was purchased by Briggs Stratton some years ago, however some information is available at the following web address, just enter your model number:

http://www.generac-portables.com/service_support/owner_manuals/owner_manuals.cfm

The small board that you describe is the bridge rectifier that converts ac from the windings to dc for the armature. You can test the brush/board by removing the part from the generator and applying 12 to 16 volts ac to the input tabs/wires then test/read dc (dc voltage will be lower than input ) voltage at the brushes. Use meter to make sure that you are getting dc. I use a small power supply less than one amp that I purchased at the thrift store for a couple of dollars. If test fails replace part. If it tests ok re-install brushes and re-connect the ac power supply to brush/board which in turn will energize the armature. At this point test the armatrue for magnetic power. I use a thin welding rod or wire against armature. If you feel a magnet start the engine. If the windings are good you should get some voltage at the plugs and the two wires that feed the brushes (will not be full voltage). If voltage is present, kill engine and disconnect ac power supply and connect the original wires to brushes/board and start engine. If you now have voltage at plugs you spiked the system indirectly by energising the armature. If still no voltage you may have an open circuit that feeds the brushes or diode pack is failing with the incresased voltage. Good luck with your repair and email if you have questions.

well I have a special flasher unit but I believe you can put 12 volts to the brushes while it's running. That should do it.

To flash the excitor circuit on a coleman ( the generator is built by generac) you need a 12 volt battery. You quickly apply 12 volts via your 120vac recepticals. NO MORE THAN ONE OR TWO SECONDS! Then check you ac voltage. Most of the time the brushes are burnt up when voltage is low. Check the brushes first. You can access them by taking the end cap off of the generator via two to four screws. The brush holder is easy to spot, two wires leading to the front of the amature. Hope this solves your problem.

Good Luck with that...but if engine runs and there is no output voltage, that generally means that the stator needs to serviced or replaced (likely as pricey as a new genny).

I’m happy to assist further over the phone at https://www.6ya.com/expert/robert_aad3edb7dfa380b9