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Author Topic: 87 onan nhe 6500 genset emeralrd 3 issue  (Read 452 times)

Thunderhawk

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87 onan nhe 6500 genset emeralrd 3 issue
« on: December 22, 2017, 03:16:39 PM »
Iv got a 1987 onan genset emeralrd 3
Model# 6.5 NHE-1R126100A
Serial# A870 86121A
The problem is control board is bad so i bypassed it got gen all tuned up and
Runs great now but output voltage is 4 volts
My question  since im new to onan gensets does the control board turn on output
Voltage or is my problem deeper such as a stator & rotor replacement big differance
140 dollars for a control board
Or 500 to 800 for the others
Thanks for the help in advance

rls7201

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Re: 87 onan nhe 6500 genset emeralrd 3 issue
« Reply #1 on: December 22, 2017, 05:47:33 PM »
Some of the best generator info is at Smokestack. Scroll down about a page to find what you need.
https://www.smokstak.com/forum/

Richard

Thunderhawk

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Re: 87 onan nhe 6500 genset emeralrd 3 issue
« Reply #2 on: December 23, 2017, 02:37:44 PM »
Ok ill check it out thanks

Lou Schneider

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  • Posts: 8410
Re: 87 onan nhe 6500 genset emeralrd 3 issue
« Reply #3 on: December 23, 2017, 07:37:22 PM »
Yes, the voltage regulator has to put voltage into the field coils (on the armature) or the generator won't put out voltage. 

Did the engine run until you released the "Start" switch?  If so, your control board may be OK because it won't let the engine continue running unless it sees voltage from the generator and good oil pressure from the engine.  Missing either of these will make the engine shut down when you release the switch.

Another good source of information is www.flightsystems.com

They make nice replacement boards if that turns out to be the problem.

Page 3 of their Onan Troubleshooting Guide shows how to tell if the problem is in the control board or in the generator itself.  Follow the steps under (4) Check If Engine Keeps Running.

If the genset sat for a while, you may have corrosion on the slip rings that is preventing the exciter current from getting to the armature.  Flight System's Slick Stick is a handy way to clean the slip rings without having to disassemble the generator.
« Last Edit: December 23, 2017, 07:57:48 PM by Lou Schneider »

Thunderhawk

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Re: 87 onan nhe 6500 genset emeralrd 3 issue
« Reply #4 on: December 25, 2017, 10:49:48 AM »
The gen done nothing with switch when i got it
Found several broken wires and with out
Knowing where they went i said screw it till
I got gen running right so i bypassed the control board got gen tuned up i now have info
That supports the info that rectifier needs
Flashed with 12v so im going to test and flash it
With 12v next run test and see if i get output voltage
If not i will go from there with checking other possible problems bad rectifier, slip rings, etc thanks

« Last Edit: December 25, 2017, 10:52:03 AM by Thunderhawk »

Thunderhawk

  • Guest
Re: 87 onan nhe 6500 genset emeralrd 3 issue
« Reply #5 on: December 27, 2017, 04:57:51 PM »
Testing revealed a bad bridge rectifier one diode shorted out gen is in camper though has
Been all this its in no way 100% i have been
Waiting to get it putting out voltage right
Before continuing install still got to get fuel tank setup