Generator switch

[Chrave]

I’m having a problem I hope some one out there can help with. My Onan 6000 quiet diesel generator won’t start unless the ignition key is in the running or accessory position. I could run an always hot wire over to the switch, but I don’t know which color wire to tap it to. Any suggestions on solving this?

[dougrainer]

You just purchased the RV less than a month ago. So, Has the Genset EVER started by itself without the Key on or ACC? Doug

[opnspaces]

Unplug shore power and turn off all engines. Find where the batteries are connected to the transfer switch. Take a voltage reading there and see if you have 6 or 12 volts.

[Chrave]

Actually, the 2 house batteries were the first thing I replaced when I bought the RV (July 10, 2021). The 2 golfcart batteries had frozen and cracked with the previous owner.

[dougrainer]

Chrave wrote:
Thanks, Doug
The system worked okay until I left the key in the ACC position overnight and drained the vehicle batteries. Everything charged back up, but the gen developed the issue after that.
Is it certain that Tiffin wired the gen to start off of the house battery system?

Tiffin wired the Genset almost all to the Coach batteries. There are some over the years that were wired to chassis but very few. The Fact of your posting the 4 items is positive that your genset is wired to the Coach batteries. Remember, you stated that you DID replace the Coach batteries after your initial charge up of both banks. There is NOTHING that would cause a Genset starting problem by leaving the Key on other than draining both battery banks. There is no electrical part that would fail from leaving the key on. Doug

[Chrave]

Thanks, Doug
The system worked okay until I left the key in the ACC position overnight and drained the vehicle batteries. Everything charged back up, but the gen developed the issue after that.
Is it certain that Tiffin wired the gen to start off of the house battery system?

[dougrainer]

Chrave wrote:
The 2 coach batteres are new. 700 cca each and 12.6 volts at check. But the corrosion is a possibility. Thanks for the tip

Since you changed the batteries, odds are you MISSED a cable connection at the coach batteries. When a battery system and appliances WORK before you replace batteries and then you have an appliance that does NOT work after replacement, YOU have miswired or did not connect a cable. You would be amazed how after 42 years as a RV tech customers swear on a stack of bibles they connected EVERYTHING correctly and when they bring the RV in in less than 5 minutes I find the unconnected/miswired cable. Doug

[Chrave]

The 2 coach batteres are new. 700 cca each and 12.6 volts at check. But the corrosion is a possibility. Thanks for the tip

[dougrainer]

Chrave wrote:
Thanks for responding
The issue started when I accidently left the key on and drained the batteries. I charged them and they tested “good condition” at 900 cca (rated 950 cca new).
The gen will start and stay running under these conditions:
1. The ignition is in the ACC position
2. The ignition is in the on position.
3. The main engine is running.
4. The ACC start switch is pressed and held down. Once tge emerg start switch is released, the generator will stop

OK, The Gen SWITCH is wired DIRECT to the Genset. No other external wiring. SO, from this update you posted, the COACH(not chassis) batteries are either DEAD or you have a corroded connection at the Coach batteries. Since the main Engine starts, your Chassis batteries are good. When you do the 4 items above you are connecting the CHASSIS battery to the Coach batteries and THAT is supply the 12 volts to start and run the Genset. Doug

[Chrave]

Thanks for responding
The issue started when I accidently left the key on and drained the batteries. I charged them and they tested “good condition” at 900 cca (rated 950 cca new).
The gen will start and stay running under these conditions:
1. The ignition is in the ACC position
2. The ignition is in the on position.
3. The main engine is running.
4. The ACC start switch is pressed and held down. Once tge emerg start switch is released, the generator will stop

[rlw999]

Chrave wrote:
I’m having a problem I hope some one out there can help with. My Onan 6000 quiet diesel generator won’t start unless the ignition key is in the running or accessory position. I could run an always hot wire over to the switch, but I don’t know which color wire to tap it to. Any suggestions on solving this?

Is this new behavior that you're trying to diagnose, or has it always worked this way?

If it's new behavior, your house batteries may be undercharged or going bad and you can only start the generator when the ignition switch is on and it closes a solenoid connecting the house and chassis batteries.