Short in the ACC pole

[Tom_Barb]

Our motorhome 2002 Newmar Mountain Aire, 8.3 cummins has a short in the Accessory side of the ignition circuit.
When you replace the fuse, and turn the key to ON- or - Acc, the fuse blows.

The ignition switch has been replaced. ---- same results
all circuits for the Accessories have been disconnected. --- still blows the fuse
Connecting the fuse to the ACC pole of Ignition switch and the fuse (+) show continuity.

The Cummins computer tool will not turn on, it requires the ignition to be turned on, which blows the fuse.
All the relays In the coach have been tested all fuses and been checked.

due to the dead engine the air is depleted "0" so the breaks are locked.

[MountainAir05]

Tom, when you loose the tone in the frame, are they any chance that you have vent holes in the frame. If not find where wires come out and start checking there. Also I am sure you have looked for the same color where you loose the tone to where the wires come out of the frame. Ohm from the blown fuse side (fuse removed) to ground and see what you come up with. A lot of wires to check but it can be done. Insure that your battery is off or the fuse is pulled.

If you leave that wire off , what does not work and that gives you place to start.

Gene

[dougrainer]

So, the ACC and IGN worked AFTER you replaced the batteries?
Also, you DID change the Inverter/Charger settings for Lithium batteries? This would not cause your problem. Just want to make sure you know to change the charge parameters when going Lithium.
Also, have you rechecked to make sure you have NOT left a wire loose or misconnected at the battery compartment? This may mean you have to pull the batteries to make sure there is not a loose wire that got pinched and you missed when doing the batteries. I had a customer that replaced his batteries in his Airplane hanger on his 04 Essex and NONE of the 4 slides would work and they were extended and had to pay me for a long distance Service call. Took me 5 minutes to find the cause. His dedicated Slide 12 volt supply wire at the coach batteries was loose and behind the battery tray. He SWORE he doublechecked everything before paying me to come out. Doug

PS, Have you disconnected the shore power AND the coach batteries and then checked for a short?

[Tom_Barb]

dougrainer wrote:
You understand that the chassis system is NOT the only system that uses the ACC or IGN side of the switch? There are numerous Coach and dual coach/chassis circuits that are energized by the ACC or IGN side of the key switch. Jack system. Bi directional charging system. Ign controlled various parts of the Dash controls(not the instrument cluster) like the Dash AC system. Have you done ANYTHING to the RV recently that may point to a short in the system. Doug

I replaced the chassis batteries, I've replaced the coach batteries to Lithium, the coached has worked normally since then.
all systems work except the ACC side of the switch.

[Tom_Barb]

BurbMan wrote:
Have you contacted Newmar? They may have an electrical schematic on file in their archives that can tell you where to look.

Yes! they say it is a Spartan problem. and yes I have a skit for the system.

[dougrainer]

You understand that the chassis system is NOT the only system that uses the ACC or IGN side of the switch? There are numerous Coach and dual coach/chassis circuits that are energized by the ACC or IGN side of the key switch. Jack system. Bi directional charging system. Ign controlled various parts of the Dash controls(not the instrument cluster) like the Dash AC system. Have you done ANYTHING to the RV recently that may point to a short in the system. Doug

[BurbMan]

Have you contacted Newmar? They may have an electrical schematic on file in their archives that can tell you where to look.

[Tom_Barb]

Flute Man wrote:
It will probably take a skilled electrical person with the meter to find it. I can maybe help you over the phone and give you some troubleshooting hints. I am a skilled professional electrical troubleshooter.

I have been using a tone generator and have traced the wires into a 2.5 inch conduit leading into the frame, then the generator looses it.

[Flute_Man]

It will probably take a skilled electrical person with the meter to find it. I can maybe help you over the phone and give you some troubleshooting hints. I am a skilled professional electrical troubleshooter.