GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.

Home » Public Forums » GMCnet » ONAN starting (starter stays engaged after starting)
Re: [GMCnet] ONAN starting [message #320832 is a reply to message #320829] Sat, 22 July 2017 10:54 Go to previous messageGo to previous message
Ken Burton is currently offline  Ken Burton   United States
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma:
Senior Member
I am sitting here looking at the Onan Wiring diagram that Colonel Ken made. +12 volts should always be on one side of the K1 coil. The Onan board controls the K1 coil by applying ground (-12vdc) on the opposite side of the coil. There is one wire from the K1 coil to pin 7 on the Onan board. There should be no other wiring connections to either the coil terminal or pin 7 on the Onan board.

That said, Pin 7 on the Onan board goes only to the N/C point of K2 and no where else. So when K2 is powered by the 33VAC from the alternator, the K2 N/C point should open up and block any path to the ground side of K1. So at this point I would suggest that you have a wiring error, or a short on the board, or a tacked relay point on K2. Even if you had a tacked relay point, the voltage should drop to K1 when you remove your finger from both of the starting switches.

I guess that there is a possibility that there could be a worn spot on the coil that when energized the armature might short to. I have never seen this but it is the only idea that I have right now on what could be causing this problem. That is just a wild guess because I have never seen of or heard of this failure.


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana

[Updated on: Sat, 22 July 2017 10:57]

Report message to a moderator

 
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: Tank sending units
Next Topic: 403 passenger side exhaust manifold needed in midwest
Goto Forum:
  


Current Time: Thu Oct 31 20:04:19 CDT 2024

Total time taken to generate the page: 0.01160 seconds