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MJMichelle · 07-06-2014, 10:50 AM

Electrical issue in 1990 Las Brisas

So, as I mentioned in a previous post, we are having some problems with our new (used) motorhome.

We had a 2 hour drive to bring it home, and barely made it here.

We have no owners manual and don't know where to start.

The battery indicator on the dash shows that the battery is barely holding any charge. We lost lights/signal lights... etc because it was so dead.

We ended up flipping the auxillary switch to the other side ( no idea what its for but it worked) and we made it a few more miles before that battery started to die. We managed to make it home by switching the auxillary switch back and both.

Upon arriving home, we checked the batteries. Both are showing a 12 volt charge on my husbands meter.

But the motorhome won't start, even with the start boost held down.

Where do we go from here?

mike9999 · 07-06-2014, 04:07 PM

A fully charged 12V battery should have about 12.6-12.7 volts.

Have the voltage meter on the battery when you try the starter. If it drops low (below 10-11V) then you have a low battery and need to charge it.

Sounds like you may have an alternator problem so it's not charging while the engine if running.

If you can jump start it the battery should show 13.6V or more while charging on the alternator.

MJMichelle · 07-06-2014, 04:35 PM

The cabin battery is showing 13.2V with ignition off.
The chassis battery is showing 12.18V with ignition off.

It won't start - just barely turns over once and then buzzes.

We have a 10A charger on the chassis battery right now.

both batteries were installed brand new last month (show an April 2014 date on them) so they should be in decent shape.

dscotty99 · 07-07-2014, 09:39 AM

Check the solenoid battery isolator. When I got mine, nothing on the chassis electrical system worked. No horn, aux fans, power mirrors, etc. Battery voltage good. Fiddled around, found the battery isolator solenoid in the basement right next to the door. $25.00 for new one. Now everything works.

MJMichelle · 07-07-2014, 10:13 AM

After having the battery charger on, and the trailer plugged in to shore power.... both batteries are charged.

Now the starter just grinds as if the starter is only half engaged.

MJMichelle · 07-07-2014, 10:15 AM

and can someone explain the point of the "auxilliary" switch on the dash? Not the "start boost" button, the one beside it?

Richard S. · 07-07-2014, 03:56 PM

The AUX switch is for dealer installed options, per the National RV owners manual.
My switch was used for dash fans.

chboone · 07-07-2014, 04:39 PM

Try posting your problem and need for manual on the Yahoo Groups National RV Forum. You'll need to join to post. It has over 2,800 members, someone may be able to help with the manuals. Don't expect to much from the manuals they are very generic and basic. However, they will tell you what the switches are for and some of the other items in the coach. Nothing is connected to my auxiliary switch.

Chuck

chboone · 07-07-2014, 04:47 PM

Check all the ground connections at the batteries and chassis. Remove them and clean to shiny metal. A coach of that age my have loose or corroded connection, especially if it's been in Canada all it's life.

Chuck

MJMichelle · 07-07-2014, 10:00 PM

We've pulled the starter... its cracked. New one coming tomorrow.

All battery connections and wiring are new so that's all good.

Only time will tell what's wrong with our guy.