I have a generator that does not produce any volts. I replaced the brush block because it was bad with no help. I took resistance readings of the rotor and stator. Are these in spec?? briggs and stratton model 09719-3 with a generac 5000 watt generator rotor 26.2 ohms stator red/blue .4ohms stator blue/gray .7 ohms stator gray/red .5 ohms

Hi and welcome to FixYa, I am Kelly.

Without a model number... I am guessing about what type / brand and MODEL of generator you have. I have to assume it is a Coleman Power mate.

Try flashing the field. Do this.. take and electric drill and plug into the outlets of the generator. Turn on the output power GENERATOR ON. Squeeze the drill trigger and rotate the chuck as fast as you can. This will induce voltage into the stator and they usually will start producing power. When it does produce power it will try to yank the drill chuck head out of your hand so keep that in mind.

If the above does not work...
Remove the small cover from the center of the endbell. It covers the end of the rotor shaft and has 2 brushes under the cover.
INSPECT the brushes visually (do not remove them yet)
(Generator OFF!)
Use a meter to read resistance by probing the electrical contacts of the brushes. You MUST read LOW resistance. This is the rotor winding.
No resistance or high resistance
Remove the brushes inspect for damage. Try to probe the slip rings of the rotor. (You might have to make a 14/2 Romex electiral wire extension to get some solid copper wires to touch the rotor slip rings) Again you must read LOW reistance.

If you have low resistance and the brushes are good.....
Reinstall the brushes. (TEST for AC) Start generator
STILL NO OUTPUT?!!!!
Use a meter on DC to read AVR voltage output to the brushes by probing the brush terminals. You should read 3 - 7 VDC. No voltage.... hmmmm Possibly an AVR problem but...

Try this.
Rig up a 9 Volt battery that you TAPE the wires to the battery terminals and the case of the battery
Just loosely connect the 2 wires to the brushes. Wrap the battery with a rag it might explode if you don't remove it fast enough. Your going to yank this off as soon as it produces power QUICKLY.

Plug in a light or a small fan so you can see that power is being produced. Let it run a few minutes before shutting it down.

To do anything else I need to know your generator model number to do winding and voltage regulator checks.

Thanks for choosing FixYa,
Kelly

Hi and wleome to FixYa, I am Kelly.

Pull off the small cover on the OUTSIDE of the end bell that covers the bearing and the brushes. Using a meter on resistance scale of R X 100 or R x 1000 probe the brushes and see if you read any resistance You should see a reading of much less than 1000 ohms that would be the rotor winding resistance. If you do not have resistance then remove the brushes and check the condition and LENGHT of the brushes. The brushes should be no less than 3/8" long. If you can get your test leads into the brush holes probe the slip rings and read the rotor resistance. You must read resistance under 500 Ohms. No resistance or can not reach the slip rings remove the end bell and test rotor resistance again but probing the 2 slip rings.

Most of the time the brushes wear out or break off when a generator just suddenly stops working.

Reinstall the end bell and read for a DC voltage reading of 3 - 9 volts across the brushes after you know the brushes are in good working order. No voltage then the AVR has failed. If you have voltage then the final tests would be continuity checks of the diode and capacitor in the end bell and finally the stator windings. The dilde will ony read resistance in ONE direction. It should NOT read open or shorted in both directions. The capacitor check use R x 10,000 and probe the capacitor terminals. Reverse the leads and probe it again. You should see a brief jump in resistance and the meter will drift to infinity EACH time you reverse the leads.

If you want parts information I need the model number off of the unit data plate to get that information for you.

Thanks for choosing FixYa,
Kelly

Hi Jake and welcome to FixYa. I am Kelly. Check both CB1 and CB 2 circuit breakers by pushing them to OFF and then back ON. Open the brush block access and then start the unit. You should read voltage at the brushes of 5 - 14 VDC on the terminals of the brushes. If you do not have 5 - 14 VDC at the brushes the probable suspect is the automatic voltage regulator (AVR). If you do have the correct voltages then with the unit OFF.... do a resistance check across the armature coil by reading resistance at the brush block terminals. You should read around 180 Ohms. It can be more or less resistance but for sure less than 500 Ohms. If you do NOT get a resistance reading remove the brush block assy and test the armature directly by reading across BOTH slip rings. You should get the resistance previously stated. If you have resistance then most likely there is a problem with the brushes. (Too short / broken carbon brush / missing spring or a defective terminal.) Without knowing the AVR output voltage and the armature resistance reading at this point it is difficult as to how to advise you to proceed. Let me know the values you obtain for AVR DC voltage at the brushes and actual ARMATURE resistance reading. Make sure you use R x 1000 on the meter. I am having thoughts of maybe a broken wire somewhere inside the control panel also.

Thanks for choosing FixYa,
Kelly

I have the same problem and here is my troubleshooting steps I took.

1) Verified that the unit had no output with induction meter on cables coming out of top of generator head (three black and three white). You can use a volt meter too.
2) Checked that brushes were free and long enough.
3) Checked capacitor (condenser) was 130uF
4) Checked diodes

Take a resistance reading across the brushes with and Ohm meter. (not running) You should read a low resistance. If you have no resistance across the brushes then then either the brushes are not mating with the armature or the the armature is open.
IF you have resistance then the AVR (Automatic Voltage Regulator) in the endcap has failed. With the engine running and the Brush block disconnected you should have 4 - 12 VDC on the two wires going to the brush block. No voltage = bad AVR.

Thanks for choosing FixYa.

Kelly

Stator resistances should be around .5 ohms. This may look like a short to you. Unhook the regulator from the field brushes and put 12 volts on the field winding. you should get output to partially light a bulb..maybe 60 volts. Remember to use 12 volts dc on the fields and don't reverse the polarity.
If there is output then the avr(voltage regulator) is probably bad. If there is no voltage then check the resistance on the brush contacts. through the bushes and field. Maybe around 25 ohms. Your generator manual can give the exact ranges. No resistance then clean the brushes and slip rings and check again. No resistance...take reading on the slip rings. No resistance...open field...bad rotor. Good luck....keep posting until problem is resolved.

Replace the sockets they have most likely gone bad, I have found this on a lot of generators I've worked on.

Check to see if this unit has brushes and rings. If it does, then make sure that the brushes are making a good contact on the rings. If the contact is good, then your voltage regulator could be bad. This would require more troubleshooting.

Check excitor coils, they produce power from the generator head..