Community Forums

jdporter221 · 10-18-2016, 05:30 PM

I have a 99 winnebago chieftain with a Onan emerald plus generator that will not start using the starter switch on dash nor the panel over stove. IF i hold the aux power switch in it on the dash panel while pushing the start button on the console, it starts. It will not start if you push the start button on the generator.
this problem just started last weekend on a trip to the Smokies. Any suggestions where to start looking? also primer no longer works on generator.

Skip426 · 10-18-2016, 05:37 PM

So if using the " boost switch " on the dash and feeding power from all the batteries to the gen set ; it will start.

Without the boost switch activated , does the gen set turn over at all ?

The gen set usually starts from the coach batteries , have you load tested those batteries ?
Have you checked the battery connections on the gen set for good power and that they're tight ?

jdporter221 · 10-18-2016, 05:53 PM

it will not crank with out the aux power switch

jdporter221 · 10-18-2016, 05:57 PM

first thing I checked. Both coach batteries at 13.6v

Skip426 · 10-18-2016, 06:02 PM

You need to check the cables , between the batteries and the gen set, first for power at the gen set , if no power then trace the cables back to the batteries, there may be an inline fuse or circuit breaker that's tripped.
My chassis has a 135 AMP, inline fuse to protect the cable, against shorting out.

NOTE: Poor connections at the batteries can cause this condition too. Gen set starter draws a lot of power compared to the rest of the 12 volt coach systems.

EDIT; And the starter draws way more power than a digital multi-meter; have you tried measuring the coach battery volts while someone hits the start switch ?

twinboat · 10-18-2016, 06:03 PM

Re-check the house battery, positive and ground connections. Check the ground cable on both ends.

They are the only two connections that get bypassed with the boost switch.

Skip426 · 10-18-2016, 06:10 PM

Quote:

Originally Posted by jdporter221

first thing I checked. Both coach batteries at 13.6v

If you're on shore power , which I'll assume your on, with a volt reading over 12.7 ( fully charged battery voltage). The gen set starter draw may be over loading the converter charger if the batteries are low.
What volts do the batteries read with shore power disconnected?

jdporter221 · 10-18-2016, 06:19 PM

does anyone know if there is a relay or solenoid hidden somewhere in the chassis or behind a panel?

Invisable · 10-19-2016, 02:59 AM

Quote:

Originally Posted by jdporter221

does anyone know if there is a relay or solenoid hidden somewhere in the chassis or behind a panel?

The solenoid and relay are typically near the generator starter. The on/off switches in the coach activate the relay. If the relay was the problem, none of the switches would work.

I am in the process of replacing my stolen Onan with a bigger, different brand generator. I am going to locate (move) my relay to the front of the frame for use of future repairs. My solenoid is attached to the starter.

Good luck. Sounds like a breaker is tripped. Check your wiring diagram.

Jim

twinboat · 10-19-2016, 05:36 AM

The large 12 volt breaker, for the generator, is in the cable running to the generator. If tripped, no power would get there no mater what the boost switch was doing.

The boost switch adds the chassis batteries to the house batteries.

mojoracing · 10-19-2016, 09:47 AM

Will the chassis batteries start the main engine? That would tell you first and foremost if they have enough juice to start the gen, then you could check the wiring to gen.