6.3 NHEFA onan LP generator circuit board

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burdenh
Posts: 16
Joined: Sat Oct 31, 2020 8:25 am

6.3 NHEFA onan LP generator circuit board

Post by burdenh »

Working on the generator in a 97 Safari Sahara generator that starts and runs but stops as soon as the start button is released. Is there a secret to disconnecting the wiring harness from the circuit board at the left top of the circuit board? I have tugged and pulled on the blue plug of the wiring harness to try to get it off the circuit board but no luck. I do not want to break the plastic plug that attaches the wiring harness to the circuit board. I need to remove the circuit board to get access for more work. What am I missing? Thanks, Hubert
05wingrider
Posts: 104
Joined: Sun Oct 27, 2019 7:26 pm
Location: Spokane, Washington

Re: 6.3 NHEFA onan LP generator circuit board

Post by 05wingrider »

Hubert,
I believe that there's a nylon lock piece on the side of it that is holding it into the connector (most of the electronic stuff like that has a lock pin/plug), so you need to see if you can find it and see if it requires being depressed to release, or what the exact combination is. Sorry I can't give more help at the moment, but my rig isn't parked here at my house for me to go out and look to see what it takes to remove the connector. I don't know if you've seen the attached or not, but here's a troubleshooting guide from Flight Systems that may be of assistance.
Attachments
onan-rv-troubleshooing-guide.pdf
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Duane
96 Sahara 30', 250hp Cat 3126
Allison 6spd MD-3060
2015 Jeep Cherokee Trailhawk "Toad"
Spokane WA
burdenh
Posts: 16
Joined: Sat Oct 31, 2020 8:25 am

Re: 6.3 NHEFA onan LP generator circuit board

Post by burdenh »

Duane, Thanks for the note and yes I have the troubleshooting guide from Flight Systems. Still working on the exact combination to depress/release the wiring harness from the circuit board. Seemingly such a routine, simple procedure. Starting to think the connections are corroded/stuck together. Already managed to break part of the blue plastic depression tab on the wiring harness. I'll keep at it. Hubert
burdenh
Posts: 16
Joined: Sat Oct 31, 2020 8:25 am

Re: 6.3 NHEFA onan LP generator circuit board

Post by burdenh »

Well, I finally disconnected the plastic connector where the wiring harness attaches to the circuit board. Took a lot of brute force and awkwardness. This allowed me to remove the circuit board and get access to the voltage regulator. Cleaned the circuit board with a Q tip and 91% isopropyl alcohol. Replaced the voltage regulator with a Flight Systems # 305 voltage regulator and all is well. Now I have to order that special tool from Flight Systems to clean the slip rings. Great to be up and running again.
Hubert
stuplich@ymail.com
Posts: 1146
Joined: Mon Oct 28, 2019 8:51 am

Re: 6.3 NHEFA onan LP generator circuit board

Post by stuplich@ymail.com »

burdenh wrote: Mon Mar 22, 2021 11:10 am Well, I finally disconnected the plastic connector where the wiring harness attaches to the circuit board. Took a lot of brute force and awkwardness. This allowed me to remove the circuit board and get access to the voltage regulator. Cleaned the circuit board with a Q tip and 91% isopropyl alcohol. Replaced the voltage regulator with a Flight Systems # 305 voltage regulator and all is well. Now I have to order that special tool from Flight Systems to clean the slip rings. Great to be up and running again.
Hubert
Hubert
The slip rings can easily be cleaned using a piece of green Scotch Pad attached to a stick of wood.
https://www.youtube.com/watch?v=U7s0ZAkbtro
Mel
'96 Sahara 3530, mine since '01
250 hp 3126 Cat, MD3060 Allison
CactusTwo
Posts: 70
Joined: Mon Oct 28, 2019 12:06 pm

Re: 6.3 NHEFA onan LP generator circuit board

Post by CactusTwo »

Hubert,
I too recently got my Onan propane working and DID get a Slick Stick from Flight Systems. I found out that it was tight to get it by the cooling fins so I filed two of the slots wider and straighter with an 8" bastard file (Onan off) just the width of the file. Oh! so much easier now
Len and Brenda Nugent
Alberta, Canada, fulltimers since 2012
1996 Safari Serengeti 3740 front door, bought in Feb 2019
Cat 3126 300hp, Allison MD3060, VelvetRide suspension
sold 2008 GMC Duramax 3500 and 37' Cedar Creek 5th wheel
burdenh
Posts: 16
Joined: Sat Oct 31, 2020 8:25 am

Re: 6.3 NHEFA onan LP generator circuit board

Post by burdenh »

Len,
Thanks for sharing your experience. My tool is ordered from Flight Systems and I guess I'll do the same thing as you. It does look mighty tight between those cooling vents.
Hubert
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