Question for the Onan Gurus

CGeils

Member
Oct 10, 2013
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I have had the GMC for just about seven years now. A good bit of that time has been spent fixing stuff, but we have taken 2 cross country trips and
put about 10k miles on it. In that time we have used the Onan very little as the dash A/C works and most camping has been within 50 ft of a 110
outlet. But the Onan has worked well, starts pretty easily and runs smoothly. This year I’ve had to start jumping terminals 9 & 11 together to by
pass the fuel pump / ignition circuit relay so I bought a Dino board for it. There has been one PO mod that has always bothered me and I would need to
address before installing the new board. It has a jumper wire from a ground stud below the K1 solenoid to the lower pin #1 on the board. It appears
the OE wire to pin 1 was cut and taped after exiting cavity 4 on the connector. The other end goes to the ground side of the K1 solenoid.
In studying the Onan wiring diagram Pin #1 is a ground but it is not clear where to me they actually attach to ground. So I thought I can clean this
up, remove the jumper and extend the cut wire back to pin 1 so it’s grounded via K1 ground stud. When I tried to crank the starter the solenoid
clattered at about 4 or 5 Hz. Ok so let’s try running pin 1 to the ground stud rather than the solenoid ground by moving the ring connector. That
works! Cranks fine. My wiring is now cleaned up, install the Dino board and now it starts and runs great. But what’s the deal with the two ground
paths? The wire from cavity 4 to the K1 ground stud looked like a factory installation. I don’t have a good wiring mechanization (the one in the
Onan manual is not “good”!) to know where they intended the pin 1 wire to attach to ground. I assume a bracket stud is where it should go to
ground?
Lastly is anyone replacing the relays on the OE boards? Otherwise it is a good board.
--
Chris Geils - Twin Cities / W Wa
1978 26' Kingsley w/ very few mods; PD9040, aux trans cooler, one repaint in stock colors, R134a, Al rad, Alcoas, 54k mi
 
One of the relays - K3 - has no direct replacement although there are some older P&B relays that will work. The coil resistance is critical since the
shutdown for low oil is accomplished by shorting K3 and letting its series resistor dissipate4 the 12V as heat. I found some relays
some years ago which were the proper resistance. Since they're only one pole NO contact, I use them to switch another relay glued on top with greater
contacts and contact current capability. Ken Henderson found an acceptable substitute, but I don't think it's available any more. The other on-board
relay is a straight up 12V, replacement is easy to find. 'Shotgun' the capacitors and diodes on the board and it should run just fine.

--johnny
--
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
 
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