Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-09-2011, 08:50 AM   #1
Winnebago Camper
 
Join Date: Jan 2010
Posts: 6
7.0 kw onan gen no output

I have a 95 winnebago motorhome with a39M 7.0 kw marquis gen. model#7HNMFA26105D serial#1943228987.It has 154 hours on it.It runs,but it won't produce AC volts.Last fall lady bugs got into the tranfer switch and fried the diodes when it was on shore power.Replaced them and it worked fine on shore power.I checked brushes,breakers,and even tried excitingit at pin 9 through a diode,and still no power.Any help would be greatly appreciated.I'm thinking it might be regulator. Thanks in advance. Jack
jaque1 is offline   Reply With Quote
Old 10-09-2011, 02:52 PM   #2
Winnebago Owner
 
Dave78Chief's Avatar
 
Join Date: Jun 2009
Posts: 149
Did you mean "7NHMFA26105D" vice "7HNMFA26105D"?

If so, then the Service manual is 965-0531B (http://www.cumminsonan.com/www/pdf/m.../965-0531B.pdf). A description of how the generator section works and troubleshooting it is in section 8.

Dave

Dave
__________________
Dave in Virginia
1978 Winnebago Chieftain
Dodge M400 - 440-3
Classic Winnebago Site: http://www.classicwinnebagos.com/forum/index.php
Dave78Chief is offline   Reply With Quote
Old 10-09-2011, 03:41 PM   #3
Winnebago Owner
 
Join Date: May 2006
Posts: 82
Jaque1,

One of my gen sets had it own circit braker locaded on the unit which would trip ever so often, it would run, but not send current to the tranfer switch.
__________________
Bob and Bev

06 Itasca 40' Horizon KD
Party Barge is offline   Reply With Quote
Old 10-09-2011, 05:19 PM   #4
Winnebago Owner
 
Dave78Chief's Avatar
 
Join Date: Jun 2009
Posts: 149
If this is a 7NHM unit, then the fact the engine runs after you release the start switch says a lot. Initial excitation is via VR1 pin 7 from the battery. This is used as field voltage across VR1 pins 9/10. This is working because your getting output from stator leads B1/B2 which generate engine run/battery charge voltage via VR2. This also starts voltage generation from stator leads Q1/Q2. When you release the start switch, B+ is removed from VR1 pin 7 therefore the source to continue field excitation is from the Q1/Q2 leads. That votage is rectified in VR1 and used for F1/F2. All that is working or the engine would not run. THis leaves you with the T1-T4 stator leads, the VR1 120VAC output voltage regulation, the harness wiring, the generator CB's, the wiring to the transfer switch or the transfer switch itself. Are you seeing voltage at the generator CB's and/or the terminal board?

Dave
__________________
Dave in Virginia
1978 Winnebago Chieftain
Dodge M400 - 440-3
Classic Winnebago Site: http://www.classicwinnebagos.com/forum/index.php
Dave78Chief is offline   Reply With Quote
Old 10-09-2011, 05:23 PM   #5
Winnebago Watcher
 
Join Date: Oct 2011
Location: North Carolina
Posts: 1
sound like the voltage regulator
wchipper is offline   Reply With Quote
Old 10-09-2011, 05:31 PM   #6
Winnebago Camper
 
Join Date: Jan 2010
Posts: 6
My mistake on model#. It is 7NHM.Sorry !I'll check it out some more this week and keep you up todate.Thanks Jack
jaque1 is offline   Reply With Quote
Old 10-16-2011, 10:17 AM   #7
Winnebago Camper
 
Join Date: Jan 2010
Posts: 6
Dave, I checked for 110 voltage at pin 9&10 and nothing.Going to winterize it and worry about it in the spring. Jack
jaque1 is offline   Reply With Quote
Old 10-19-2011, 10:19 PM   #8
Winnie-Wise
 
Join Date: Jul 2010
Posts: 336
I just came across a guy with the same problem on a Onan 4000 kw just this last weekend; started right up, ran great, no a/c power. Turned out to be something very simple: the breaker tripped on the generator. A teenager actually found the breaker, as it is small in size and located down low, all but hidden. I probably wouldn't have found it without a manual pointing me in the right direction. While I doubt I would be so lucky (always costs me money to make a repair) you might check just to make sure it's not the generator breaker.-RT
RTegarini is offline   Reply With Quote
Old 10-19-2011, 11:06 PM   #9
Winnebago Camper
 
mr300ce's Avatar
 
Join Date: Oct 2010
Location: Lancaster, California
Posts: 15
ONE of my 2 breakers tripped. Then only 1 of the a/c units would work at a time. I found the breaker on the back side of the genset. Mine is a 7000, also. Find those breakers, and flip them. Maybe that is all you need.
__________________
'94 Bounder 32h. Chevy V-8 44k miles and like new. Tow 4 down '85 Nissan 4x4 Kingcab
Retire in 1yr. 3mo. , but who's counting
mr300ce is offline   Reply With Quote
Old 10-21-2011, 06:17 AM   #10
Winnebago Camper
 
Join Date: Jan 2010
Posts: 6
mr300ce,I flipped the circuit breakers many times and still no power.Thanks! Jack
jaque1 is offline   Reply With Quote
Reply

Tags
onan


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
1999 UA - Use of Gen-turi on Gen exaust daellishou Electrical | Charging, Solar and Electronics 7 02-25-2010 03:24 PM
Onan 4BGE 4000 gen set mustang Electrical | Charging, Solar and Electronics 6 11-08-2008 06:15 AM
Onan gen set TAN Electrical | Charging, Solar and Electronics 6 09-23-2008 08:40 AM
New Sunova Issues - Onan Gen - Inverter bccsrc Electrical | Charging, Solar and Electronics 8 04-09-2007 08:00 PM

» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Winnebago Industries or any of its affiliates. This is an independent, unofficial site.


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 03:56 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.