Community Forums

Vongreg · 07-10-2021, 06:55 AM

I am wondering if the OP is talking about the ignition switch.

bduemig · 07-10-2021, 07:58 AM

I just tested mine. Started the generator. Turned off coach and chassis disconnects inside the coach. Generator remained running. Mine is a generac 75d, not an Oman

swduns · 07-10-2021, 08:29 AM

If he's talking about the 12VDC coach power disconnect switch
the typical RV requires 12VCD coach power if you are occupying it

12VDC coach power is needed:

- for RV refrigerator, even when on gas
- for interior lights
- for Air conditioning units, because thermostats require it
- furnace
- water heater on gas

etc.

Mudfrog · 07-10-2021, 11:46 AM

Quote:

Originally Posted by Joshj

The coach switch has to be on to start the generator, when I turn the coach switch off the generator also turns off, it just started doin this last week

Again, why are you wanting to turn off the coach switch?

There may be a specific reason that you are turning it off but in normal situations, it needs to be left on. The converter not only provides 12 volts to the coach, its charging portion keeps the batteries charged.

THenne1713 · 07-10-2021, 11:22 PM

In the old days (when ALTs were new technology), you could disconnect battery to test ALT; if it continued running, ALT was putting out.. MODERN VEHICLES will lose control and you RISK blowing alternator and/ or computer, I have read.. NOT RECOMMENDED

THenne1713 · 07-10-2021, 11:26 PM

(sUSPICION) IS THAT on the Generac, it might die within 3-5-minutes, (if battery disconnect shut down the FUEL PUMP?); OTOH, if GEN Power to CONVERTER (MIGHT) supply power to the Fuel Pump?

twinboat · 07-11-2021, 03:10 AM

Quote:

Originally Posted by bduemig

I just tested mine. Started the generator. Turned off coach and chassis disconnects inside the coach. Generator remained running. Mine is a generac 75d, not an Oman

Does that D stand for diesel ?

Diesels don't need 12 volts to run, just start.

THenne1713 · 07-11-2021, 11:30 PM

Re: DIESELS and 12-volt? Yes and NO, if fuel is gravity fed, like a tractor/ lawn mower w/ fuel tank above; NOT so when 12vdc controls FUEL PUMP and/ or FUEL SHUTOFF SOLENOID?

THenne1713 · 07-12-2021, 10:10 AM

Rereading/ rethinking all, I suspect we are confused over your terminology. If you are saying you turn IGN switch= ON, this should engage the CHARGE SOLENOID, which connects (chassis/engine) battery voltage to the Coach Battery. If coach battery switch is off, or coach battery bad, or bad Battery ON/OFF solenoid, (if solenoid** used vs manual switch), or just a bad coach battery CONNECTION (corrosion?), this would explain problem. GEN MUST HAVE BATTERY VOLTAGE to run fuel pump to continue running. CHECK YOUR COACH BATTERY? (under step?) (**"Battery Disconnect Latching Relay" is used in some RVs, controlled by a Center-Off Rocker MOM Switch)

bduemig · 07-12-2021, 11:02 AM

Quote:

Originally Posted by twinboat

Does that D stand for diesel ?

Diesels don't need 12 volts to run, just start.

Yes, the d stands fire diesel. I didn't know that diesels don't need 12v power to run.

CRV2 · 07-12-2021, 11:13 AM

Quote:

Originally Posted by bduemig

Yes, the d stands fire diesel. I didn't know that diesels don't need 12v power to run.

A diesel engine itself, especially the older ones never needed 12v power to run. However, almost all modern diesels, especially those used in RV, Trucks, etc., require 12v for the control circuits and computers, fuel solenoids, pumps, etc. It sounds as if you are losing 12v power when you turn the key off.

What I would check is the coach batteries voltage and follow the cables and power flow back to the generator as it sounds as if there isn't any 12v to the generator when the key is off. ~CA

avfordguy · 07-13-2021, 11:26 PM

Some generac diesel generators need to hold down the start switch for 15 seconds after it runs to energize the stator.

THenne1713 · 07-15-2021, 12:31 AM

Also just recalled one owner bought a rig, found GEN would ONLY run if coach running; determined wrong fuel pump and wrong GEN fuel connecton (was piped to Return Pipe, so could ONLY get fuel when main pump running; had to replace main pump and install correct part

THenne1713 · 07-15-2021, 11:36 PM

I feel there is some CONFUSION over your use of the term "coach switch"? If this is the coach BATTERY ON/OFF switch, (COACH BEING DEFINED AS LIVING AREA), then this switch should ALWAYS BE ON when in Use, and ONLY OFF during storage when NOT plugged in (TO REDUCE battery drain during storage), but if plugged in, Leave ON, so battery/ ies can CHARGE. Hope this helps?