Generator won't start

victorino545 · April 1, 2015

Have a Discovery Class A and having problem with generator not starting unless the engine is on. Can anyone give me some suggestions and what to look for. Newbie to this so any help appreciated.

scouserl41 · April 1, 2015

A little more information would help.

I'm guessing you are cranking and cranking it with the engine running to get it started, but have you primed it before you start?

There is usually a button alongside the generator start button which you hold down for around 30 seconds which primes the carburetor on the generator before starting.

Are you using that button?

The generator isn't used very much so the fuel can evaporate over time and leave the carburetor dry. It takes time to get fuel to the carb.

As it obviously starts when the engine runs I'm guessing that might be the problem. If the chassis battery is strong enough to start the engine then I would think it's not a voltage problem.

Once it starts for the first time does it start easily after that? If so then it is a lack of priming IMHO.

That's one of the reasons for starting the generator once a month and letting it run against a load (Usually and AC running) for an hour or two.

Hope this helps.

BnB

Jim & Alice · April 1, 2015

Any problem with running the generator monthly... and staying hooked up to shore power? Never tried it, always took precaution of shutting off power at the pedestal.

HB

socaltoolguy · April 1, 2015

I'm sure you already know this but if not, make sure you have more than a 1/4 tank of gas. If it gets below that it won't start and continue running.

Ray

don&penny · April 1, 2015

I'm not sure what having the engine running has to do with it not starting but - I had some friends with a problem where they could not start their generator in their Class A. It turned out to be the battery disconnect switch having been placed in the "disconnect" position. The switch did not have any visible indicators to show which position it was in.

Don

Kirk W · April 1, 2015

Since your generator starter draws power from the coach batteries and the chassis starter from the chassis battery, running the chassis engine gives you additional power because once the engine comes up to speed there is a relay that closes to supply any excess power available from your chassis alternator to the coach battery, or in this case to the starter for your generator. I'd suspect that you have a problem either with the coach batteries or the charging of them.

horizon36 · April 2, 2015

To prime a diesel generator press and hold the stop switch for 30 seconds. Also, if you press and hold the stop switch for about 10 seconds you will get a blinking error code from the switch which you can look up in your manual.

Smitty77_7 · April 2, 2015

Have you tried starting the generator with only the boost battery switch helping out? If it starts that way, as well as when the engine is running, then I'd take a good look at the battery and the feeds to the generator. May just need some wire/ground connections cleaning, that the extra juice of the engine running compensates for...

Best of luck to you!

Smitty

NJ-Ron · April 2, 2015

When ever I had trouble starting my gas operated generator (not turning over) it was usually the coach battery (deep cycle) that didn't have enough juice to start the genny. As Kirk stated starting the engine supply's the power to start the generator. Sometimes my deep cycle battery would not get charged because a 175 amp for that circuit had blown. Since I learned that was the issue I always carried 2 spare 175 amp fuses, one for the house battery and another for the chassis battery.

Ron

Keelandb · April 8, 2015

I have to agree with Kirk. In our Class C if the coach battery is at all low the generator will not start. In that case we start the engine and then start the generator.

BobK

oldjohnt · April 9, 2015

I'm with Kirk on this also. On many RV's I've owned the genset starts via the house batteries. However, if they are discharged and cant crank the genset over, once the engine starts and the alternator and engine battery are then in parallel with the house batteries, theres enough power to crank the genset over. If the genset starts fine if your connected to shore power I think the same, because then (or at least after some time elapses) the RV's Converter/Charger has had time to bring the house batteries up sufficient to crank the genny over.

I think tis time to have your house batteries checked for state of charge and specific gravity and load tested as it doesn't take that much capacity to crank the genset

NOTE the above assumes your house batteries is what cranks the genset and your engines alternator and engine battery is connected in parallel with your house batteries once the engine is up and running and any time delay has passed. If that's NOT your configuration I will have to change my thinking.

John T