RV Repair: Electrical started a fire..., itasca rv, starter solenoid

Question
But luckily I was able to put it out before it burned me to the ground.  

I recently acquired an 85 Itasca RV on a Chevy P-30 chassis.  We've had a few problems with it but for the most part the electrical has worked as advertised except for some non functioning dash gauges.  

The other day we after cruising for 3 hours we stopped to take a break and when we returned to the coach after about 10 mins, there were sparks coming from the battery bay and several wires had caught on fire.  I quickly disconnected all the batteries and sprayed the area with an extinguisher and got the fire out.  Apparently I had stopped the shorting so I carefull re-connected the auto battery, made sure it wasn't shorting and took off for home, made it no problem.  

It's been a couple of weeks and I finally worked up the nerve to look behind the batteries and see what I could see.  There is a starter solenoid behind the batteries, I assume for the generator or to start the engine from the house batteries.  Several wires have melted/burned insulation, there is one loose wire with a spade connection floating free and the end of a fusible connection (old radio maybe) that is also hanging loose.  This coach used to have a fairly elaborate sound system that was connected directly to the auto battery-professionally wired, not a hack job but I have been running without any sound system hooked up since this is a restore/re-model and it was been in the way for the most part.

As I looked closer, I grabbed the right side of the  solenoid (as viewed from the front) and the connecting post came off in my hand.  So that's a problem.  I also noticed that the small post (right front) has nothing connected to it-seems a perfect fit for the loose wire with the spade connection on it.   

I should also say that the starter was recently replaced professionally so I am wondering if maybe the mechanic hooked the stereo system wires back to the battery since the wiring is still in the bay (I disconnected it when the fire started.)  

I guess I need to know if it is likely that the solenoid failed causing the shorts of if a short and fire caused the solenoid to fail?  I have been racking my brain to see if I can recall an event that started the problems and all I can think that I did was switch the battery charging swtich on the dash that causes the house batteries to charge off the alternator.  

I have a wiring schematic from Winnebago, so I may be able to figure some of this out but I am pretty nervous about putting my family in a fire hazard.  

Any help/advice is greatly appreciated.

John

Answer
Well John i'm sorry for your situation but with a problem as this is,probally not a major one without looking at it for myself i don't wan't to steer you in the wrong direction.  This is serious and I would hate to have something happen to you and your family, Get it seen by a Rv dealer or a mechanic to be safe.  That solenoid you seen is either a house battery disconnect or a solenoid to join the house and starting batteries for jumping the starting battery.  The way they work is a small low voltage wire is connected to a smaller post to close the terminals inside to join the house batteries to either the starting battery or to disconnect the power to the coach to save the house batteries.  I'm sorry I can't be of more assistance but this is somthing that really can't be solved without troubleshooting it in person.  Good Luck.
Shawn