My RV's Generator Only Starts When The RV Is Plugged In

by Dana
(NM, USA)

My RV's Generator Only Starts When The RV Is Plugged In

My RV's Generator Only Starts When The RV Is Plugged In

I recently bought a 97 PaceArrow. When the owner was showing it to me, he started the engine, pushed the button for the generator and it started right up.

A couple of weeks later when I went to pick up the coach, the generator wouldn't start. The fridge wouldn't come on either. They plugged the coach into the house using an extension cord, and then everything worked. The generator would start and the fridge worked.

FREE coverage for your spouse & dependent children. Good Sam Roadside Assistance. Learn More!


I asked him when he last topped off the water in the auxiliary batteries and he said, "they need water?" They are about three years old. The water was quite low, so they filled it up with tap water. Now it shows a full charge, but the generator still won't start. Just get click-click-click-click. Do you think it's just the auxiliary batteries that need to be replaced or something else wrong? They power the house lights fine. Thank you!

ANSWER: Hi Dana my gut instinct tells me that you need to replace the house batteries as they are not strong enough to start the generator. If the generator still starts with the RV plugged in, then that tells me that the starting problem is not due to the generator.

Good Sam Extended Service Plan is mechanical breakdown insurance for your RV, 5th Wheel, Trailer, and Tow Vehicle! FREE Quote

Even though you say that the 12-volt interior lights are working off of the battery; that does not mean that the batteries are providing enough
juice to start the generator. One thing you mentioned in your question disturbed me "I asked him when he last topped off the water in the auxiliary batteries and he said, "they need water?" They are about three years old. The water was quite low, so they filled it up with tap water." You should only use Distilled water in the batteries, never tap water. Tap water has minerals and impurities that can damage a battery.

The only way to determine if you need new batteries is to run a few tests. I am going to refer you to the answer I gave to this question Our RV Interior Lights Only Work When We Are Plugged In Or Generator Is Running. In the answer, I gave I outlined some troubleshooting steps they needed to perform to find out what was wrong with their electrical system. You should start at step 3 on that page.

Again I am pretty sure that your batteries are the problem. It is just a good practice to eliminate every other cause before going out and purchasing new batteries.

If any of our visitors have suggestions for you they can add them to this page by clicking on the add a comment link located near the bottom of this page.

Do you have any suggestions or comments on this topic? You can add them to this page by clicking on the "Click Here To Post Comments" link located near the bottom of this page.

Happy RVing

RVing Al

Join the Good Sam Club Today! Discounts, Tips, Tools & Much More!

Comments for My RV's Generator Only Starts When The RV Is Plugged In

Average Rating starstarstarstarstar

Click here to add your own comments

Rating
starstarstarstarstar 		Generator problem.
by: Anonymous

when we got our new to us motor home, we had the same issue, found the plug in the motor home above the power cord that hooks to the house was unplugged from the coach, we plugged it in and everything worked fine. And it was hidden below the closet, not an easy find. I think that's why the people sold it was because they couldn't make it work and were fed up with it.
Rating
starstarstar 		connection,
by: dano

You failed to mention checking grounds at frame from generator, and positive leads to generator, the problem goes away with the extra boost from the converter while plugged in.

Totally agree that batteries most likely weak....any good technician can load test them...
Rating
starstarstarstarstar 		Generator won't start
by: GPappy

What is the voltage at the batteries? There should be at least 13 volts with NO load on them. What does the voltage of the batteries do when you are starting the generator? Clean ALL battery connections first.Then try to start the generator. If the voltage drops way off when trying to start the generator then the batteries are the culprit. It also isn't a good idea to have the RV plugged in to shore power with the generator running, but...Is everything OK when the generator is running and you remove shore power?

Click here to add your own comments

Return to Ask an RV Question.

LEARN HOW TO RUN 2 RV A/Cs ON A 30 AMP CONNECTION