Fob will not unlock doors; MH won’t start

[wbeldin]

Hello, I have replaced both under the floor batteries with new ones. The motorhome started yesterday, but today it will not unlock the doors with the fob. I entered through the side door but the motorhome will not start. After pushing the button below the ignition, the key will turn and the motorhome started. Is this start procedure normal for starting? And should I replace the key fob?

Thank you in advance for your assistance as I navigate this new adventure!

[Midnightmoon]

What year/model motorhome do you have? Is this on a Ford or Mercedes chassis?

[JimD]

Odds are your battery under the hood is weak. That battery is used to unlock the doors and start the engine. When you pressed the dash button you connected your coach batteries to the engine battery which allowed the engine to start because they were charged up.

[wbeldin]

2019 Mercedes Melbourne Prestige

[bucko]

Sounds to me like the "house battery/batteries" are good, but the chassis battery is weak or dead. Pop the hood (or where ever Mercedes keeps the chassis battery) and have this battery load tested. Most auto stores will do this for you for free.

[Midnightmoon]

Chassis battery will be located under the floor in front of the driver's seat if it is a single battery system.

[TWP723]

If may have to be flashed at the dealer. When you remove both batteries usually. Also depends on how long they were out.

[Ann-Marie]

Keep in mind that your "shore" power only charges the RV batteries, it will not charge the starting battery. There is a simple technique to solve this problem.

[Pfflyer]

Here are a couple of threads that may help you.

https://www.jaycoowners.com/forums/f...rne-42254.html

https://www.jaycoowners.com/forums/f...ing-53015.html

https://www.jaycoowners.com/forums/f...des-79995.html

If yours is a 2019 MB chassis there may be a small "Auxiliary BATTERY" under the drivers seat that will probably give you issues if your starter battery has been drained. I dont think that is cause of your key fob not working but something that may pop up.

https://www.jaycoowners.com/forums/f...ion-77965.html

The earlier version of the MB Chassis had a old fashioned key hole in the drivers door that you can use instead of entering through the coach. Not sure if yours has the same but I cant imagine it not being there.