SMC and Chassis Power Out

[John Demartini]

Starting having a problem with SMC, only lifting rear and not reaching proper level.  Manual retract would work, but intermittently getting jack warning while driving and applying brake.  Application of manual retract switch would quiet the alarm.  Parked last night, attempted to operate system this morning, heard one jack seat and then system went dead.  Now I have no ignition power or chassis power.  Chassis Batteries test good.  House jump button lights up the SMC panel, but will not provide enough to start engine.  SMC manual shows 15 amp breaker at CB42, and 15 amp ignition breaker at CB24.  Can these breakers be reset?  Are these located in front electrical box, under drivers area?  Or are they like a fuse and need to be replaced if blown.  I suspect one of these has tripped.  Any suggestions or advice would be greatly appreciated.  Thank you.

[Steve Huber Co-Admin]

John,
The circuit breakers are thermal circuit breaker. They trip when overheated (too much current draw) and reset once they cool down. The ignition breaker should not play into this issue at all. Sounds like your house batteries may be drained. If you can start your generator, run it for about an hour or more to recharge the batteries before trying anything else, or if on shore power, be sure your battery charger is on.
Steve

[John Demartini]

Thank you Steve.  Running generator now.   I also stay hooked up to shore power at home, 120v 20amp.  Not sure about charger being on?  Never has to worry about this as the house batteries always stay well charged.  Is there a location of a switch that I can check?

[Steve Huber Co-Admin]

Battery charger status should be indicated on the Inverter display. Alternately check the house battery voltage, If 13V or higher the charger is on.
Steve

[Eric Maclean]

John
You stated that you have lost all chassis and ignition power this indicates one of three things .
1 ) the ignition solenoid in the electrical bay has gone bad
2 ) the main chassis ANL fuse has blown
3 )the main chassis disconnect switch is not turned on or gone bad

First check would be at the ignition solenoid in the front electrical bay under the driver the solenoid is located at the bottom of the buss bars with all the circuit breakers.there should be power on one of the larger wires at all times this is the chassis battery feed to the solenoid and all the always hot circuit breakers if you have not power to either side of the solenoid this would indicate there is no power coming from the chassis battery bank ( posible causes 1 blown ANL fuse, 2 battery disconnect switch or dead battery,
3 battery cable connections .

If there is power to the solenoid turning on the ignition switch should activate the solenoid and power should now be on both larger wires and all the circuit breakers should be powered if this doesn't happen there are two causes one the solenoid has gone bad ( this is the most likely fault and many us have experienced this failure )or two the ignition switch in the dash is bad (not likely)

My bet would be the 250 amp chassis ANL fuse for the chassis this will be located either under the bed or in the battery bay near the disconnect switches depending on your coach year model and floor plan.
I believe it will be under the bed on ones side of the other of the battery boost solenoid.

The fuse will look like this
https://www.amazon.com/Vehicle-Marine-Audio-Video-System/dp/B081VVLLKW/ref=sr_1_5?hvadid=233482947327&hvdev=t&hvlocphy=9006609&hvnetw=g&hvqmt=e&hvrand=17385382156540664690&hvtargid=kwd-31947175889&hydadcr=18886_10145462&keywords=250+amp+anl+fuse&qid=1698840433&sr=8-5

Hope this helps
Eric

[Dan Johnson]

Sounds like a good part to have on board. What is the part number of the ignition solenoid which would be a good part to have also?

[Eric Maclean]

Dan
The solenoid is a Cole Hersey continuous duty solenoid rated at 85 amp or higher I have links here for an 85 amp and a 200 amp unit you can buy cheaper solenoids but the quality may be questionable.
A good continuous duty solenoid will have silver contacts which helps them survive high in rush amperage without arcing and burning the contacts.

It's a good idea to carry one as the ignition solenoid is known to be a failure point this solenoid can also be used to replace the starter primary solenoid if needed.


https://www.amazon.com/Cole-Hersee-24059-Insulated-Continuous/dp/B000Y82X4E/ref=sr_1_7_sspa?hvadid=580742645006&hvdev=t&hvlocphy=9006609&hvnetw=g&hvqmt=e&hvrand=3579912360250109231&hvtargid=kwd-331790669736&hydadcr=5767_13191244&keywords=200+amp+continuous+duty+solenoid&qid=1698876788&sr=8-7-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9tdGY&psc=1


https://www.amazon.com/Cole-Hersee-24213-Continuous-Solenoid/dp/B005K2429I/ref=sr_1_3?hvadid=580742645006&hvdev=t&hvlocphy=9006609&hvnetw=g&hvqmt=e&hvrand=3579912360250109231&hvtargid=kwd-331790669736&hydadcr=5767_13191244&keywords=200+amp+continuous+duty+solenoid&qid=1698876788&sr=8-3

Hope this helps
Eric

[Fred Brooks]

   To temporarily prove that the solenoid is the issue, use a battery jumper cable and connect it to the lugs of the solenoid on the 3 o'clock position and the 9 0'clock position. This will in effect by-pass the solenoid. If you are in transit and the solenoid fails, you can by-pass the solenoid by removing one of the cables and reinstalling it on the other side of the solenoid. (when you stop driving, you will have to disconnect the cable or you will have a dead battery).
  Incidentally, as Eric suggested we all carry a spare Cole Hersey solenoid in our tool box. Fred

[John Demartini]

Thank you for all the suggestions.  Ultimately found blown ANL fuse for leveler pump.  Replaced fuse and chassis power restored.  Now I just need to figure out why the leveler pump blew the fuse.  Only rear jacks are activating, maybe a valving problem?  No leaks are present so I believe the fluid level is good.  Any suggestions are greatly appreciated.  Thanks again...

[Eric Maclean]

John
On an SMC leveling system the jacks are daul action and each jack has two hoses one to retract and one to extend in order to move an single jack the valve has to open on end of the cylinder to the tank while pressurizing the other end
If the control demand a cylinder to move it will activate the pump and activate a pair of valves to make the cylinder move
If the valves don't operate the pump will run up against the pressure relief valve effectively dead heading the pump.
This may be the cause of your blown ANL fuse.

Try to manually operated each of the cylinders in manual mode to see if you have a cylinder which doesn't extend and makes the pump work too hard once you have determined which jack is at fault try trading a valve cartridge or coil to see if the fault moves with that valve cartridge or coil.

Remember Do Not operate a coil without it being installed on a valve cartridge as this will burn out that coil.

Hope this helps
Eric

[John Demartini]

Hi Eric:

Thanks for the advice, but I'm not sure about manual mode.  I have "Auto" and "Semi Auto".  Is there a diagnostic mode that allows manual operation?

[Fred Brooks]

    John,
  If you go to the blue banner at the top of the page and click on technical and scroll down to coach assist, this will take you to our library of all the manuals concerning your coach. Under leveling systems you will find SMC leveling, On page 5 it will tell you how to level your coach under "semi-automatic" including all the time delays. Hope this helps! Fred