HVAC trips DC Control Fuse - 2009 Camelot

[jfasano88]

My ac dc is tripping my fuse. It is blowing my 10am fuse. Can someone help me with this issue. My fuse also does my T- sat and tv atenna. Why is it blowing my fuse?

john 2009 Monaco Camelot kfq 

[Trinidaddave]

The purpose of the fuse is to protect your wires. You will need to find the reason that circuit is drawing over 10 amps.

Do you have a meter, every owner should carry a meter even if they don’t know how to use it.  In time you will become comfortable using it.

You can start your troubleshooting by pulling the fuse and searching for the short using the resistance setting (ohm) scale on all the devices you mentioned on that circuit.

You can disconnect all the items you said were loosing power when fuse blows and replace the fuse, then reconnect them one at a time. This will isolate your trouble to a specific component.

This may take some time, but it’s the only way to find the short unless you can just physically look at the wires and find something obvious.

[jfasano88]

Thanks I did unplug the tv antenna but don’t know how to find the T-SAT is t-sat my thermostat and how do I unplug them. 
Buy the way when I change the fuse my ac works for a while and don’t know when it blows the fuse. It happens when the units shut down when temperatures are reached and when I turn off the units at night. The next morning I have to change the blown fuse  

John 2009 Monaco Camelot kfq 

How do I find the short when it is working. How do I use my multimeter on the telephone wires or do I find other wires that are not telephones rj-11. Where do I put the prongs into the telephone wires  

John 2009 Camelot kfq 

 

[Trinidaddave]

I would disconnect the power in the control panel inside the unit. 
 

Your air conditioning unit may need to be serviced!  If the unit is dirty, motors need oil or airflow is restricted it could be why your unit is drawing the high current and blowing the fuse.

Again you should have a clamp on ammeter to check the current of the compressor and fan motor.  
If you are able to open the unit these meters will tell you a lot about your equipment.

good luck!

[Ivan K]

Is it a single AC unit doing that? There are no moving parts that run on 12V. If you using a slider switch on thermostat to turn them on/off, does it feel a little off, like wigly or unreliable? I had to resolder mine once, before I upgraded it.

[Tom Cherry]

1 hour ago, jfasano88 said:

Thanks I did unplug the tv antenna but don’t know how to find the T-SAT is t-sat my thermostat and how do I unplug them. 
Buy the way when I change the fuse my ac works for a while and don’t know when it blows the fuse. It happens when the units shut down when temperatures are reached and when I turn off the units at night. The next morning I have to change the blown fuse  

John 2009 Monaco Camelot kfq 

How do I find the short when it is working. How do I use my multimeter on the telephone wires or do I find other wires that are not telephones rj-11. Where do I put the prongs into the telephone wires  

John 2009 Camelot kfq 

 

From the basics as a 2009 Camelot owner.  FIRST, you need to understand HOW this works....otherwise, I would not have a clue to tell you where to begin checking voltages and such....or start to trouble shoot.  If this overwhelms you, then you will need to get a Technician....it is NOT as simple as "push that button and all is well"

BUT....I have addressed TWO KNOW Camelot issues.....and also given you a step by step set of instructions.  You do NOT need a VOM....all you need are some small wrenches and sockets and a $10 part and then tighten up all the incoming power connections to the fuse box.  I THINK it is there....and not an issue with the HVAC.  BUT.....that is an educated guess.....

There are THREE prints that you need to look at.  BUT first, since you are new and MIGHT not understand some of the electrical systems, there are TWO Safety Concerns that MUST BE ADDRESSED....if you have to get a Tech, then he can do them....

Look at the HIGH Current Distribution - 12 VDC PRINT. . 

NOTE.....you have a dangerous condition in your Motor Home.  Monaco installed the WRONG circuit Breaker up front in the lower left corner.  It is what controls or protects your Hydraulic system  It will have 150 Amps on it and a lever and is black.  That SHOULD be changed.  You can use a 100 Amp one.  Amazon has them.  OTHERWISE, you WILL (I know and I did) burn out your hydraulic motor.  This is IMPERATIVE. Technically, it should have been an 80 Amp.  I burned up my hydraulic and I am running the 80....but the 100 will provide protection....your call.  

Then open the Genny and roll it out.  On the RIGHT side is the Hydraulic system.  There is a large "box" with TWO lugs.  That is the START THE PUMP solenoid for the Hydraulic.  Check the nuts on that solenoid and tighten the nuts.  Don't go crazy buy make sure they are TIGHT.   There is Power on the incoming side (long cable).  It comes from the Circuit Breaker in the front bay that needs to be replace.  The other one is OK.  It is safe to work on them unless someone would try to move one of the front slides.  

Next, follow the cable to the MOTOR.  You MUST use a small wrench or socket and take off BOTH cables.  Remove the washers, nuts and cables.  There is a NUT under them.  This NUT keeps the studs (the threaded bolt) TIGHT inside the motor.  It is PROBABLY LOOSE.  Use a proper size wrench or socket and snug it down.  Again...hand tight....so don't twist it off.  Reassemble and all will be well.  If that STUD is loose, then you have a high resistance connection inside the motor.  When that happens, the current flow increases as well as the voltage dropping.  SO the SLIDE moves slow...and eventually WILL kill the motor.  That entire motor and valve assemble and reservoir is almost $2,000....and about $900 labor.  FIX these.  This is Preventative Maintenance.  VERY IMPORTANT....We have had many failures over the years and I( have been on this board for over 13 years and 11 of which was a Moderator and a "Helper"..  DO NOT THINK THIS IS UNIMPORTANT...

Finally....Look in the last bay on the Passenger side....the one beside the Propane tank.  Your ATS is in there.  Look at it.  It will be to the RIGHT of the White Magnum Inverter.  If it says IOTA 50R....then it is a FIRE and PERSONAL SAFETY item.  It can (and it HAS) catch fire.  These were recalled by Navastar when they owned Monaco. OPPS....your Motor Home, like mine was an ORPHAN, so Navastar was not LEGALLY required to replace them.  You need a NEW ATS.  The most popular and reliable ATS, as used by many if not most here, is the ESCO LPT50BRD.  That needs to be done and you need to have it done promptly.

OK>>>>THAT IS THE BACKGROUND TO KEEP YOU and YOUR FAMILY and MH SAFE.....

Your thermostat is NOT powered by any 12 VDC line.  There is a Control Box in the roof top unit of each HVAC box.  That control box does all the work and makes the system work. The control boxes send out low current voltage to the Thermostat.  There is NO direct connection of 12 VDC power to the Thermostat.   If you look at the Air Conditioning Wiring print, notice that there is a 12 VDC Line going to each one.  That line is marked Satellite If I remember.  It is the one that is blowing.  There is NO ONE SIMPLE thing to do to fix it.  You have to start with the basics and then eliminate issues and then fix it.  

MY GUT FEEL (and this is from Experience....and others will agree and others might not).... I think you have a LOOSE power connection going to the fuse panel.  SO, the first task is to do some checks and also some NEEDED.....this is IMPORTANT.....Preventative or Maintenance on the wiring.  Otherwise, you could spend the next months chasing it and also have a hefty repair bill.....and it still not be fixed.

The FIRST step.  Jumper the Salesman Solenoid in the back rear electrical bay.  If the Solenoid has BAD contacts....then the voltage coming to it will be low....and then the current will increase....and then it will blow a fuse.  My HUNCH is when the units are cycling one, they do NOT have a full 12 VDC and then the current goes up....and then the tiny 10 Amp fuse blows.   Go to NAPA and purchase a 781144 Cable.  It is around $10.  Turn OFF the House Battery Switch and the Chassis Battery Switch.  I would disconnect the negative on each set of batteries.  If you go to the back bay on the passenger side, there is a gray box with a turn screw on it.  Open the panel.  The large solenoid is the BOOST Solenoid.  On the RIGHT is the Salesman Switch Solenoid.  Remover the nuts and put the Jumper cable on each side and tighten the nuts.  That will eliminate the Solenoid.  I would say that 90% of the folks here that have a system like yours (the Dynasty is different) have either jumpered or removed that solenoid.  MINE IS GONE.  

Next up....is to tighten the Circuit Breakers that POWER the Fuse Panel in the bathroom.  Here is how you do it.  I have been meaning to do mine....but haven't yet.  Lookc at the Camelot MUX print.  Open the cabinet doors.  You will see THREE black boxes.  These are the Intellitec Output Boxes that run your lighting system.  They are ON a panel.  You need to REMOVE the panel....they usually can be left on.  Behind that panel you will be the terminal strip left lower corner of the print.  The Salesman Solenoid provides the INCOMING power - 2G RED.  You will need to tighten the NUTS on the 5 Circuit Breakers.  The 8G Red is what goes to the Fuse Panel.  The three go to the Black Intelltiec Modules on the front.  The fifth to your bedroom potty.  If these nuts get loose...and they do, then you have a HIGH resistance Connection.

Simple.  YEAH RIGHT.  Make sure the battery switches and cables are OFF.  Once you do this....might take 30 minutes....you have eliminate the GHOST that plague MH's.  Nuts on cables loose as you drive.  Jumpering the Salesman Switch and then tightening these to make sure that you have good power will solve at least 75% of the downstream problems.

DO THIS FIRST.....It is a NEED item and will save you more headaches....than keeping your wife happy.... LOL.

OK>>>>>NOW start following the advice and also the ones that will probably be posted.  You need to shut OFF (use the MODE switch) the back and middle HVAC units.  Run the front one FULL TIME.....see if it works.  Run it over night....  If all is well.  Then add in the REAR ONE.  Run them....if all is well.....then add in the Middle one.  What you are trying to accomplish is seeing, IF THE PROBLEM STILL EXISTS??? and IT MIGHT NOT.....WHICH of the HVAC's is the problem.

MY EXPERIENCE.....we have very FEW failures of the Control Modules in each AC unit.  That is a Printed Circuit Board or Box that is inside the AC on the roof.  You have to pull each shroud or cover to get to them.  SO, I'm betting on a high resistance connection and when all three are running, the DC Voltage drops and the current goes up and the 10 Amp fuse blows.

That's my advice.  It is strictly a mechanical tightening of connections and bypassing a KNOW PROBLEM.  If you wonder what the Salesman Switch does....it was put there at the behest of the dealers so the salesmen at closing could have ONE switch to cut off everything.  NEVER MIND that it will cause owners scads of problems.  Never mind that the contacts will arc and pit.  

That's it.....GOOD LUCK>

 

2011 Camelot MUX 38110675B (Schematic Mult.pdf 12V High Current Dist TGC Rev 1..pdf Air conditioning wiring.pdf

[jfasano88]

Thanks for the advice. I have fixed it. My middle ac had grill off and I started to check the wires all look ok. Then I made sure the wires were connected tightly. Turned on the middle ac and it worked all day and night. Turned on front next day and it ran all day and night. Did the same for bedroom ac. ITT was a loose connection

thanks again John 2009 Monaco Camelot kfq                                                                          

 

 

[Tom Cherry]

1 hour ago, jfasano88 said:

Thanks for the advice. I have fixed it. My middle ac had grill off and I started to check the wires all look ok. Then I made sure the wires were connected tightly. Turned on the middle ac and it worked all day and night. Turned on front next day and it ran all day and night. Did the same for bedroom ac. ITT was a loose connection

thanks again John 2009 Monaco Camelot kfq                                                                          

 

 

Great.  Now, you know what a high resistance connection will do.  Then the wires are loose and the voltage goes down and then the current goes up.  If that had happened with an AC high current, a fire can or will result. You should now understand why electrical issues can have devastating, even fatal consequences.

my post above went into derails that are known to be dangerous and should be addresses.  The moderators and administrators want to protect members and their family and their MH from serious issues.  Please take time to read and understand the issues.

Glad you fixed it.