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Good Sam Roadside Assistance

Motorhome won't start unless RV House Batteries are used

by Anonymous

I can't start the engine on my motorhome without using the RV batteries, engine has new battery, new alternator, new starter but won't start unless I use the RV batteries by flipping the dash switch, after the motor is running if I release the RV switch the motor stalls.

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ANSWER: Hi thanks for submitting your question on our Ask An RV Question Page.

I am going to assume that you have checked the connections at the cranking battery and that they are tight and clean. You have double-checked to make sure that you have not mistakenly reversed the positive and negative connections at the cranking battery.

I am also going to assume that you have checked for any blown fuses or blown fusible link on the cranking battery.

If you have done all of the above and everything is good then I suggest that you do the following.

1. Make sure that the dash switch that you are using has not gone bad. Since the engine stops running when you release this switch it could mean the Auxiliary Battery start switch could be bad. This would be a simple fix to replace this switch.

There should also be a relay associated with this switch that may not be operating properly.

2. Even though you say that your Battery and Alternator are new; I would have them checked again as even new batteries and alternators can be bad from the factory.

Based on the information you have given me these are my best guesses on what is going on with your motorhome. Some of our visitors may be able to provide more suggestions on what you should check out to get this problem resolved.

Hope this helps.

Happy RVing

RVing Al

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Comments for Motorhome won't start unless RV House Batteries are used

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Rating
starstarstarstarstar 		RV Booster Switch
by: Brenda

We have to almost always use outr RV booster switch after driving to recrank the RV. We have added new batteries. No problems starting from cold engine but after driving a distance and maybe stop for gas we always have to use the battery booster switch? Not sure if we need new starter or alternator.
Rating
starstarstarstarstar 		just by reading
by: jacob

I found that other people were having the same issues I was having with my RV. just by reading I believe it is fixed.
Rating
starstarstarstarstar 		help
by: Anonymous

I have the same problem I have to use booster switch to crank my rv ford 450 after it cranks no problem but turn off and you have to do same thing all over again have taken the battery out and had two different shops check battery they say battery is good don't know what problem is?
Rating
starstarstarstarstar 		Battery
by: Bruce

Turns out it is a new battery that I bought in November that is causing the problem of not starting the motor, I hooked up jumper cables with a different battery to the new battery and it fired up right away, GGGGRRR isn't there any quality these days???
Rating
starstarstarstarstar 		Ground
by: Bill Anonymous

You can have a bad ground connection or cable.
Rating
starstarstarstarstar 		Motorhome wont start
by: Bruce

I want to thank the person who answered my question, it is minus 10 here right now and when it is warmer I will follow the advice given, thanks again for the help , much appreciated
Bruce

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