Electrical Mystery

[marina53]

Hi,

We are newbies to RV'ing. We have a 2004 Monaco Knight. Driving down the road we suddenly lost all power to the RV. Even turning on the generator brought us no power. We checked breakers, fuses, breakers on the inverter and still no power. We continued down the road and the power didn't restore until we shut the main engine off. Now everything is working except the water pump. Any ideas where we go from here?

Thanks, Marina and Bill

[wolfe10]

Did you loose 12 VDC to "house items"?

OR

Did you loose 12 VDC to chassis items (like the Allison shift pad)?

OR

Did you loose 120 VAC to "house items"?

[marina53]

Thanks for your reply, we didn't lose anything to the chassis. but lost both 12vdc to house items and 120vac to house items.  When we shut off the motor everything came back on except for water pump which is still not working.

[manholt]

marina53.  Welcome!

Have you checked your batteries with a volt meter?

[hermanmullins]

There are two solenoids, one that controls the instrument and one that control the starting. If the solenoid for the starting function is bad the engine will not start however the instruments will function. If the solenoid that controls the instruments goes out all contact to the instrument will be lost but the engine will still start and run.

On my coach the two solenoids can be found in the electrical panel in front of the front tire on the drivers side. A volt meter or a test light can be used to check out both. On each solenoid there should be two large lugs and one or two small lugs. With the key turned on test for power on both large lugs. You should have power to both, I using a volt meter you should have 12 volts + on each lug. If not then check for for power to the small lugs. If two small lugs you should have a Black and a White wire. On my coach the white is ground and the black should be 12 volt power. If only one small lug then it will be power and the solenoids case will be its ground. If you have 12 vols to one of the small lugs and no power to one side of the large lugs then you have a bad solenoid and it should be replaced.

When purchasing a replacement solenoid be sure that you get a  "12 volt Continuous Solenoid". That is a must.

Hope I have explained well enough how to test the solenoids.

Herman    

[-Gramps-]

Did someone by chance hit the  house power kill switch by the front door? Its in the wheel well. Happens by accident a lot in our coach. I call it the panic switch because that is what it does, causes a panic.

[tbutler]

I would start by examining the one component that isn't working.  Start with the switches for the water pump.  Check them to see if any have shorted out.  Check the water pump and the power supply to it.  If it has DC power then the pump must be bad.  If not, find out why it doesn't have power. 

Much of what you are describing sounds like the solenoids that Herman is describing and they could be the problem.  By the way, the switch that -Gramps- mentions is connected to one of those solenoids, the "house power" runs through that one.  You can test this by bypassing the solenoid, connect the incoming 12V wire to the output 12V wire (a solenoid is just a switch, connecting the two wires does the same thing as flipping a switch, completes a circuit).  The "panic switch" -Gramps- refers to just activates that solenoid switch.  In our coach I removed the solenoid that controls the house batteries after several had failed.  I simply wired the two 12V wires together.  The switch by the entry door now does nothing.  If I want to cut battery power to the coach I have to go to the main switch (near the battery compartment) to turn off the power.  It is less convenient but really, how often do you need to cut all power to the coach.