Good Sam Club Open Roads Forum: Short in the ACC pole
Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Class A Motorhomes

Open Roads Forum  >  Class A Motorhomes  >  Maintenance Issues & Tips

 > Short in the ACC pole

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 3  
Prev  |  Next
Matt_Colie

Southeast Michigan

Senior Member

Joined: 10/09/2011

View Profile


Offline
Posted: 04/26/21 05:57pm Link  |  Quote  |  Print  |  Notify Moderator

Tom,

I have done diagnostics on systems that looked a lot like your situation. I am guessing that the ACC circuit comes out of a gang plug on the ignition switch...
If that is the case, can you identify that wire?
If you can, remove that wire from the gang plug. This is just about always possible, but it is never easy (we seem to be way past easy) and it may take a special tool to release the latches that hold that connector in the plug body. When it is loose, now at least you can power things up and fine out what is not working. That may lead you in the direction you need to go.

Now that the system does not blow the main fuse, it might blow a single fuse for a single part of the ACC system. This could be your bast bet to track down the problem. You can now get things started.

Next cheap, dirty and very effective search method.
Now that the problem circuit is isolated, feed it power through a good sized light bulb. I have a collection of bulbs with wire leads attached but I do this more than most people. When powered up that light should light up - if there is the solid ground you reported.
Now here comes the simple and cheap part. Get a small compass. The current in that wire is creating a magnetic field that you can follow. You won't be able to follow it when it is inside the frame rail, but any place that wire is exposed, you should be able to identify it.
Sorry, I had to put a break in here.
The compass needle will lead you along. Just keep looking for the indication of current flowing, when you no longer get that, the short to ground is behind you.

Please keep us informed what you find or don't. Everything matters.

Matt


Matt & Mary Colie
A sailor, his bride and their black dogs going to see some dry places that have Geocaches in a coach made the year we married.


Tom/Barb

Oak Harbor, Wa

Senior Member

Joined: 10/16/2009

View Profile



Good Sam RV Club Member


Posted: 04/26/21 07:43pm Link  |  Quote  |  Print  |  Notify Moderator

Matt_Colie wrote:

Tom,

I have done diagnostics on systems that looked a lot like your situation. I am guessing that the ACC circuit comes out of a gang plug on the ignition switch...
If that is the case, can you identify that wire?
If you can, remove that wire from the gang plug. This is just about always possible, but it is never easy (we seem to be way past easy) and it may take a special tool to release the latches that hold that connector in the plug body. When it is loose, now at least you can power things up and fine out what is not working. That may lead you in the direction you need to go.

Now that the system does not blow the main fuse, it might blow a single fuse for a single part of the ACC system. This could be your bast bet to track down the problem. You can now get things started.

Next cheap, dirty and very effective search method.
Now that the problem circuit is isolated, feed it power through a good sized light bulb. I have a collection of bulbs with wire leads attached but I do this more than most people. When powered up that light should light up - if there is the solid ground you reported.
Now here comes the simple and cheap part. Get a small compass. The current in that wire is creating a magnetic field that you can follow. You won't be able to follow it when it is inside the frame rail, but any place that wire is exposed, you should be able to identify it.
Sorry, I had to put a break in here.
The compass needle will lead you along. Just keep looking for the indication of current flowing, when you no longer get that, the short to ground is behind you.

Please keep us informed what you find or don't. Everything matters.

Matt
Your compass trick, is a tone generator. I have traced the "10-Green wire that will emit a tone until I can no longer get to the cable bundle. then it comes in rear, there is no Green "10" wire.

I suspect there is two discrepancies. and I may confuse the issues.
Today I removed 12v power to the ACC pole in the ACC junction box, This disables the entire ACC accessories. It still blowed the fuse, I have been barking up the wrong tree.
tomorrow we try again.


2000 Newmar mountain aire 4081 DP, ISC/350 Allison 6 speed, Wrangler JL toad.

dougrainer

Carrolton, Texas

Senior Member

Joined: 06/11/2007

View Profile


Online
Posted: 04/27/21 07:49am Link  |  Quote  |  Print  |  Notify Moderator

Tom/Barb wrote:

Matt_Colie wrote:

Tom,

I have done diagnostics on systems that looked a lot like your situation. I am guessing that the ACC circuit comes out of a gang plug on the ignition switch...
If that is the case, can you identify that wire?
If you can, remove that wire from the gang plug. This is just about always possible, but it is never easy (we seem to be way past easy) and it may take a special tool to release the latches that hold that connector in the plug body. When it is loose, now at least you can power things up and fine out what is not working. That may lead you in the direction you need to go.

Now that the system does not blow the main fuse, it might blow a single fuse for a single part of the ACC system. This could be your bast bet to track down the problem. You can now get things started.

Next cheap, dirty and very effective search method.
Now that the problem circuit is isolated, feed it power through a good sized light bulb. I have a collection of bulbs with wire leads attached but I do this more than most people. When powered up that light should light up - if there is the solid ground you reported.
Now here comes the simple and cheap part. Get a small compass. The current in that wire is creating a magnetic field that you can follow. You won't be able to follow it when it is inside the frame rail, but any place that wire is exposed, you should be able to identify it.
Sorry, I had to put a break in here.
The compass needle will lead you along. Just keep looking for the indication of current flowing, when you no longer get that, the short to ground is behind you.

Please keep us informed what you find or don't. Everything matters.

Matt
Your compass trick, is a tone generator. I have traced the "10-Green wire that will emit a tone until I can no longer get to the cable bundle. then it comes in rear, there is no Green "10" wire.

I suspect there is two discrepancies. and I may confuse the issues.
Today I removed 12v power to the ACC pole in the ACC junction box, This disables the entire ACC accessories. It still blowed the fuse, I have been barking up the wrong tree.
tomorrow we try again.


READ my post again. As I stated, you are(were) looking at the problem from a chassis standpoint. Doug

Tom/Barb

Oak Harbor, Wa

Senior Member

Joined: 10/16/2009

View Profile



Good Sam RV Club Member


Posted: 04/27/21 08:59am Link  |  Quote  |  Print  |  Notify Moderator

Flute Man wrote:

Was there any incident just prior to it not working?
Jerry Parr

No, We parked the Coach and now it won't crank, and blows the fuse.

Tom/Barb

Oak Harbor, Wa

Senior Member

Joined: 10/16/2009

View Profile



Good Sam RV Club Member


Posted: 04/27/21 09:07am Link  |  Quote  |  Print  |  Notify Moderator

dougrainer wrote:


READ my post again. As I stated, you are(were) looking at the problem from a chassis standpoint. Doug


After removing the entire ACC side of the system. it now becomes clear that the ACC side is not the problem.

next step? Separate one system from the other by Disconnecting the ECU from the engine, see if the short goes away.

working on it. [emoticon]

It is not a easy place to get to. To touch the ECU the fuel filter must be removed.
Edit
There is two ECMs for the IGN, side of the Engine system, the Alison / transmittion
The Transmittion is easy , (done) we still have a short.

* This post was edited 04/27/21 09:23am by Tom/Barb *

dougrainer

Carrolton, Texas

Senior Member

Joined: 06/11/2007

View Profile


Online
Posted: 04/27/21 11:23am Link  |  Quote  |  Print  |  Notify Moderator

I am telling you to go at the problem from the Newmar COACH side of the electrical. Have you pulled the Batteries to verify you did not miss a wire or disconnect the smaller gauge wires from both the chassis batteries and the coach batteries. DON'T TELL ME YOU HAVE DONE THAT WHEN YOU HAVE NOT. I have had over 42 years customers swear they have doublechecked after they replaced batteries and they have either a short or a system does not work. They come in and in less than 10 minutes I find the loose wire or POS small gauge wire connected to the negative or a loose wire the batteries were installed on and after awhile, the weight has cause a short. Then they pay me about $100 because they were positive they had done it correctly. On your year, do you have some of the interior ceiling lights that has a 3 position wall switch? When engaged one way the lights are normal brightness and when switched the other way they have 50% dimmer brightness? Did your original Coach batteries, were they 6 volt(making 12 volt) or 12 volt and which do you have now, 6 volt(making 12 volt) or 12 volt. Last, did you do as I suggested and disconnect the small gauge wires both Neg and Pos from the Battery banks and leave just the Heavy duty large Cables connected? Then see if you have the short? Doug

Tom/Barb

Oak Harbor, Wa

Senior Member

Joined: 10/16/2009

View Profile



Good Sam RV Club Member


Posted: 04/27/21 11:57am Link  |  Quote  |  Print  |  Notify Moderator

dougrainer wrote:

Then see if you have the short? Doug

The ignition switch is out of the system. What is tripping the short is the IGN pole.

The coach system is on a circuit board, all coach systems are routed thru that circuit, That was been changed, no difference.

The Spartan circuits in the coach operate normally, the only thing that is wrong is the IGN system.
all signal lights work, back up camera, all external lights work.

Spartan's skit, shows a direct circuit to the Transmission computer and the ECU, the Transmission computer that has been disconnected. still shows a short.

I'm in process disconnecting ECU.

stay tuned

* This post was edited 04/27/21 12:12pm by Tom/Barb *

dougrainer

Carrolton, Texas

Senior Member

Joined: 06/11/2007

View Profile


Online
Posted: 04/27/21 05:08pm Link  |  Quote  |  Print  |  Notify Moderator

Lets get clear.
1. You state the IGN system. You mean it does NOT short until you turn the key all the way to engage the starter?
2. The Ign controlled COACH systems including Dash Area(Back up and so on) all work even when the other fuse blows? Doug

Tom/Barb

Oak Harbor, Wa

Senior Member

Joined: 10/16/2009

View Profile



Good Sam RV Club Member


Posted: 04/27/21 06:28pm Link  |  Quote  |  Print  |  Notify Moderator

dougrainer wrote:

Lets get clear.
1. You state the IGN system. You mean it does NOT short until you turn the key all the way to engage the starter?
2. The Ign controlled COACH systems including Dash Area(Back up and so on) all work even when the other fuse blows? Doug


The key switch excites both the ACC and the IGN at the same time. when the key is turned to either position, then you turn to IGN and continued to turn to crank.

the fuse blows as soon as either position is reached.

this is why I say there are two discrepancies.

Flute Man

Payson, Arizona

Senior Member

Joined: 03/21/2019

View Profile


Offline
Posted: 04/28/21 06:19pm Link  |  Quote  |  Print  |  Notify Moderator

Generally, there is only one fault. However by replacing disconnecting and reconnecting all those other things you can accidentally induce another fault. Exactly what fuse is blowing?
Jerry
And what size is the fuse? How many amps?

* This post was edited 04/30/21 04:40am by Flute Man *


Jerry Parr
05 Mandalay 40B
Cat C7 350
04 Honda CR-V
Ham Radio K7OU
Retired EE
[email protected]
602-321-8141
Full-timer

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 3  
Prev  |  Next

Open Roads Forum  >  Class A Motorhomes  >  Maintenance Issues & Tips

 > Short in the ACC pole
Search:   Advanced Search

Search only in Class A Motorhomes


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2021 CWI, Inc. © 2021 Good Sam Enterprises, LLC. All Rights Reserved.