Hello everyone.  I am hoping those of you with more experience with RV
electrical systems can give me some guidence before I do any damage to
my 1988 Winnebago LeSharo.

This is the first RV we have ever owned though my Mom owned one in
Colorado 20 years ago and I fell in love with it while driving it
around the front range.  I don't know if we were just driving in cooler
weather 20 years ago or what, but when we bought this LeSharo last
year, it never occurred to us that the air conditioning would not cool
the cabin.  However, after we bought it, it says right in the manual
that the air conditioning is only designed to cool the driver and
passenger while driving and I can assure you it does not even really do
that.

The vehicle is in unbelievably good condition.  Everything works and I
love driving it.  But my wife is going through "hot flashes" and during
the summer, she is just dying from the heat when we drive it. So what
is happening is that we are just not able to use it most of the time.
If we were going to drive it to a state park and park it at a
campground with a power hookup, it would be terrific.  When you plug in
the 110 power, the AC on the roof easily cools the cabin and it makes a
great environment for two 50+ people who want to camp. But the problem
is that we hardly ever have time to go camping and instead we use it
more to just drive around and stay over night at friends and relatives.
Thus the problem.

So, then I got an idea.  What if I installed an inverter to hook up to
the auxilary battery and then pluged the AC cord into the inverter so I
could use the roof top air conditioner when we were driving?  So, I
researched the power needs of the Coleman Mini-Mach on the roof.  I
found it needed 1800 watts for start up and then settled in at 1600
watts while running.  It drew around 14 amps.  So, I went on line and
bought a 2000 watt continuous/4000 watt High Surge inverter made by
PowerExpress that put out about 20 amps. Since I had no experience with
this equipement, I intitially used #8 wire to install the inverter in
the back of the vehichle near where the AC plug and other electrical
equipment is located.  I hooked it up to the  battery, plugged the AC
cord into the inverter and turned on the air conditioner fan.  It
worked great and drew only 400 watts.  Then I turned the air
conditioning on and the volts dropped from 13 volts to like 8 volts and
the inverter auto-shut off.  Upon looking closer at the inverter
instructions I found that not only was I using too small of a guage
wire, I was way too far away from the battery.

Now I had no idea where the heck I would mount the inverter if I moved
it between 2' or 6' of the battery. But to continue with the scientific
method, I disconnected the inverter, moved it to within 2' of the
battery and switched to #4/0 guage wire.  I fired up the inverter and
this time, the inverter stayed on and the air conditioner ran fine
settling in at 1600 watts.  However, the voltage on the inverter
dropped from 13 volts to 11 volts which causes the inverter to "chirp"
continuously.  I checked the volt meter in the cabin to see if the
battery was charging OK and it was not, the voltage on the battery was
down to 11 volts as well.  So, I don't think the problem is with the
battery, or the cables or the inverter.

My first thought was that the alternator was to weak to charge the
battery and hold the voltage at 13 volts.  Am I on the right track?  If
so, can I just get a bigger alternator, or is that going to mess up all
the electronics in the vehicle.  I called Mobility RV, the only company
that supplies parts for the LeSharo, and talked to a technician.  He
said the alternator on the LeSharo was 107 watts (?) but because it was
a Renault engine, he had no idea where I would get a larger alternator.
He said that he thought it could work in theory, but they knew of no
one who had ever done what I was trying to do. (Great.)  Anyway, he
also said that I may need to add a battery and run it in parallel, but
I didn't really understand what he was suggesting.

Since we are planning to have the engine running all the time while the
Air Conditioning is running, I don't really need more battery power
because the alternatore will be charging the battery as fast as we are
using it.  If I could just get the voltage up, I think this will work.
How can I do that?  Would a different inverter help?  Any suggestions
would be appreciated.

TRZ