12/1/2021: OK folks, the new forum software is up and running

Update 6/2/2022: Well, after our head knocking session with GoDaddy last month, things seem to be going smoothly. Now, when will the next "check engine light" come on {grin}?

Reminder: "quick links" menu offers you the best navigation of this forum -- you need to be registered and logged in to see that menu (details in link below). Registering is easy and free from any cost. If you have problems registering, please email me at: jim@eaglesinternational.net.

I have have created a thread that discusses the new platform: https://eagles-international.net/forums ... fa10d60ea5 Please report any issues in this thread.

Jim

New Toad. Coach won’t start.

This is a public forum to discuss Eagle related technical issues. If you are having a problem with your Eagle, this is the place to find help.
Post Reply
Eagle Driver
Club Member
Club Member
Posts: 16
Joined: Sat Nov 25, 2017 9:20 pm
FMCA #: F477671
Bus Model: 1988 Eagle 15

New Toad. Coach won’t start.

Post by Eagle Driver »

Hello Eagle-verse. Hoping for some assistance. 

My question for the group is what would have to occur for the coach to have a severe starter circuit fault or shutdown initiation at ignition start, when the tow umbilical is connected?

I recently acquired a new tow vehicle. Wiring was professionally installed on the SUV. When the electrical umbilical was connected to the coach, my coach wouldn’t start. It looked like an auto shutdown may have been initiated. I only could get one click from the starter. I disconnected the umbilical, and the coach started immediately.  Tested a second time to confirm my observation.

After starting the coach, I reconnected the umbilical and the tow setup appeared to operate normally - lights (except backup) and braking system - with no obvious negative impact to the coach electrical system. 

I have previously towed a different vehicle and never experienced this issue. The mechanic initially tested the installation by towing the Jeep behind the shop truck for a few miles with no obvious problems.  We assume something must be wrong with the wiring installation or umbilical - yet the car system appeared to work correctly when tested. We are at a loss to say the least.

In case there is something random about my setup that could partially explain the issue, I outfitted a 2021 Wrangler Rubicon (3.6L) with a Curt Manufacturing Custom Towed-Vehicle RV Wiring Harness, Roadmaster Evenbrake 2nd Car Kit, diodes, Nighthawk Tow bar (post recall), and a Victron Energy SmartShunt module to send electrical system info via Bluetooth. 

I plan to start testing with my old umbilical, to begin ruling things out. Anything that can better direct us to a more likely cause would be greatly appreciated. 
Mike

1988 Eagle Model 15 - Monaco Eagle I Conversion
DDC 8V92TA DDEC; Allison HT755CR ATEC
User avatar
beltguy
Site Admin
Site Admin
Posts: 2531
Joined: Wed Oct 08, 2008 4:39 am
FMCA #: F246286
Bus Model: 1985 Eagle 10 with Series 60 and Eaton AutoShift 10 speed transmission
Location: Evergreen, CO
Contact:

Re: New Toad. Coach won’t start.

Post by beltguy »

Wow, what a challenge! 

You have given us a ton of information - more than I can digest in one sitting:o. 

I am only vaguely  familiar with some of the things you have incorporated in the system.  I suspect you checked all the toad lights (both connected and unconneted) to make sure they work as normal.  This would tend to rule out the diodes.

I am not sure how the Roadmaster brake system is activated.  If it is an electrical controller, that would be a quick thing to disconnect to test the system.

I am not sure why you are using the shunt for the toad application.  I would guess it is to make sure the battery system in the toad is being charged as you drive.  It would be the first thing I would remove from the system for testing.

If you are using a "5 to 4" tail light converter, they have some reliability problems.

Bad grounds are notorious for causing problems.

All that said, it is strange that your rather complex system has a way of talking to the DDEC ecm.

I am sure that you have thought of all of these options.

Please keep us posted as you sleuth out the problem.

Jim

 
Jim Shepherd
Evergreen, CO
'85 Eagle 10 with Series 60 & Eaton AutoShift 10 speed transmission SOLD
2005 Dodge 2500 with 5.9 Cummins and 6 speed manual 2014 Passport 26 foot trailer
Bus Project pages: http://beltguy.com/Bus_Project/busproject.htm
Blog: http://beltguy.com/blog/
Email: jim@eaglesinternational.net NOTE this email box is only for general correspondence and not technical advice
User avatar
beltguy
Site Admin
Site Admin
Posts: 2531
Joined: Wed Oct 08, 2008 4:39 am
FMCA #: F246286
Bus Model: 1985 Eagle 10 with Series 60 and Eaton AutoShift 10 speed transmission
Location: Evergreen, CO
Contact:

Re: New Toad. Coach won’t start.

Post by beltguy »

After starting the coach, I reconnected the umbilical and the tow setup appeared to operate normally - lights (except backup) and braking system - with no obvious negative impact to the coach electrical system. 
I am not sure what you are saying here.  If the backup lights and brake system do not work after you have connected the toad to the bus, then that is a pretty good clue. 

I have to wonder if somehow the toad system is spoofing the the bus into thinking it is not in neutral (backup light not working as a clue). 

Jim
Jim Shepherd
Evergreen, CO
'85 Eagle 10 with Series 60 & Eaton AutoShift 10 speed transmission SOLD
2005 Dodge 2500 with 5.9 Cummins and 6 speed manual 2014 Passport 26 foot trailer
Bus Project pages: http://beltguy.com/Bus_Project/busproject.htm
Blog: http://beltguy.com/blog/
Email: jim@eaglesinternational.net NOTE this email box is only for general correspondence and not technical advice
Eagle Driver
Club Member
Club Member
Posts: 16
Joined: Sat Nov 25, 2017 9:20 pm
FMCA #: F477671
Bus Model: 1988 Eagle 15

Re: New Toad. Coach won’t start.

Post by Eagle Driver »

Thank you for the responses Jim.

I am using a heavy-duty 7-pin connector assembly on the coach side.  Same connections used with my prior toad.

In response to your second post, I was poorly explaining that I tested the toad functions after starting the coach and reconnecting the umbilical.  Everything worked properly on the toad except the back up light activiation.  While seeing that as an anomolie to address, I didn't consider it could be a symptom of spoofing as you suggest.

Thank you for the investigation suggestion.
Mike

1988 Eagle Model 15 - Monaco Eagle I Conversion
DDC 8V92TA DDEC; Allison HT755CR ATEC
Eagle Driver
Club Member
Club Member
Posts: 16
Joined: Sat Nov 25, 2017 9:20 pm
FMCA #: F477671
Bus Model: 1988 Eagle 15

Re: New Toad. Coach won’t start.

Post by Eagle Driver »

Update 6/21/2022:

After some trial and error, we were able to identify the issue.  The toad side of the charging line was preventing the coach from starting.  As it was explained to me, both the Allison electronics and the toad charging line are directly connected to the coach starter batteries.  Adding a diode to the toad side of the charging circuit resolved the issue.  

Jim - Thank you for pointing me towards the transmission error. 

Also, it turned out the toad backup lights were not wired to the umbilical due to the difficulty in backing with the toad attached. 
Mike

1988 Eagle Model 15 - Monaco Eagle I Conversion
DDC 8V92TA DDEC; Allison HT755CR ATEC
User avatar
beltguy
Site Admin
Site Admin
Posts: 2531
Joined: Wed Oct 08, 2008 4:39 am
FMCA #: F246286
Bus Model: 1985 Eagle 10 with Series 60 and Eaton AutoShift 10 speed transmission
Location: Evergreen, CO
Contact:

Re: New Toad. Coach won’t start.

Post by beltguy »

Mike, thanks for letting us know what resolved the problem.  Too often folks do not respond with the findings/solution.

I don't understand the circuitry (nothing new for me:D) but at least we have it documented for others that might run into the same problem.

Jim
Jim Shepherd
Evergreen, CO
'85 Eagle 10 with Series 60 & Eaton AutoShift 10 speed transmission SOLD
2005 Dodge 2500 with 5.9 Cummins and 6 speed manual 2014 Passport 26 foot trailer
Bus Project pages: http://beltguy.com/Bus_Project/busproject.htm
Blog: http://beltguy.com/blog/
Email: jim@eaglesinternational.net NOTE this email box is only for general correspondence and not technical advice
Post Reply