Reply
 
Thread Tools Display Modes
 
Old 11-19-2019, 06:33 PM   #1
Bus Nut
 
banman's Avatar
 
Join Date: Aug 2019
Location: Ohio
Posts: 415
Year: 2002
Coachwork: Thomas
Chassis: Freightliner FS-65
Engine: 7.2L Cat 3126 turbo diesel
Rated Cap: 71 passenger 30,000 gvwr
Electrical Gremlins...

pOOp! I knew it wouldn't be easy but...

So my bus was running...
Problem: The engine won't turn over.

I've got two new group 31 battery's currently reading 12.75v
I get 12.75v at the red wire on the ignition switch until I turn the key to 'start'.
Then the voltage drops to 3.5v. Same readings at the bulkhead lug for the fusebox . When I measure voltage at the starter motor or the batteries themselves I still get 12.75v.
I've gone through the negative and positive connections to the chassis lugs and hot connections to the starter motor. I cleaned, and reinstalled the negative battery cables from the bat. box to the frame lug; and from the starter motor to the other frame lug, and several other leads all of which had varying degrees of rust & corrosion. But none of this changed a thing.
I can't even close the electric doors now...

BEFORE someone asks -- no, I haven't removed any of the emergency door wiring or anything else. All wiring (to my knowledge) is the same as when it last ran two weeks ago...

There is parasitic drain so I don't leave the batteries connected.

On a gas engine I'd be temped to jump the starter solenoid and see if that at least turns the engine over. With a 3126 Cat I'm not sure if that's a good idea or not...

I'm also tempted to simply run a new hot wire directly to the fuse box just so I can start and run the thing. Again, I'm not sure if there's anything that might be damaged by doing this.

Thinking about the wiring by-pass only because I'd like to move the bus a few miles to a new location for the winter...
banman is offline   Reply With Quote
Old 11-19-2019, 07:46 PM   #2
Bus Crazy
 
Join Date: Jun 2013
Location: Picton,Ont, Can.
Posts: 1,786
Year: 1997
Coachwork: Bluebird
Chassis: GMC
Engine: Cat 3116
Rated Cap: 72
New off the shelf batteries will do this without a good charge to freshen them up. That voltage is low.
check all fuses

Might have blown one in the cable work you did.
Try these for starters. Wouldn't bypass nothing yet.
Maybe give the starter a few solid taps with a BFH.
Cool weather and sitting buses are known for gremlins popping up.



John
__________________
Question everything!
BlackJohn is offline   Reply With Quote
Old 11-19-2019, 08:05 PM   #3
Bus Nut
 
banman's Avatar
 
Join Date: Aug 2019
Location: Ohio
Posts: 415
Year: 2002
Coachwork: Thomas
Chassis: Freightliner FS-65
Engine: 7.2L Cat 3126 turbo diesel
Rated Cap: 71 passenger 30,000 gvwr
Quote:
Originally Posted by BlackJohn View Post
New off the shelf batteries will do this without a good charge to freshen them up. That voltage is low.
check all fuses

Might have blown one in the cable work you did.
Try these for starters. Wouldn't bypass nothing yet.
Maybe give the starter a few solid taps with a BFH.
Cool weather and sitting buses are known for gremlins popping up.



John
What 'state of charge chart' are you using that indicates that. I'd say my batteries are at near 100%...
But even if I'm off on this, the dash cluster should still light up and the voltage gauge should show something...

The parasitic drain did discharge them, so I've already recharged them on a trickle charger. The reached a max v of 13v.

Batteries were disconnected during all my cleaning operations.

Tap the starter like an ol' dodge huh?
banman is offline   Reply With Quote
Old 11-19-2019, 08:21 PM   #4
Bus Crazy
 
Join Date: Jun 2013
Location: Picton,Ont, Can.
Posts: 1,786
Year: 1997
Coachwork: Bluebird
Chassis: GMC
Engine: Cat 3116
Rated Cap: 72
"What 'state of charge chart' are you using that indicates that?"



Oh just what I have gleaned in my long experience.


Good luck figuring this out, experts will be here soon.


John
__________________
Question everything!
BlackJohn is offline   Reply With Quote
Old 11-19-2019, 09:11 PM   #5
Bus Nut
 
banman's Avatar
 
Join Date: Aug 2019
Location: Ohio
Posts: 415
Year: 2002
Coachwork: Thomas
Chassis: Freightliner FS-65
Engine: 7.2L Cat 3126 turbo diesel
Rated Cap: 71 passenger 30,000 gvwr
Quote:
Originally Posted by BlackJohn View Post
"What 'state of charge chart' are you using that indicates that?"



Oh just what I have gleaned in my long experience.


Good luck figuring this out, experts will be here soon.


John
Thanks!

I'm sure it will be something obvious -- after I find out what it is...

All sugestions are welcome -- anything suggested gives me more to think about...

https://www.google.com/search?rlz=1C...73.bsjEjwKJu_Y

All the fuses were good. Mostly they're circuit breakers so no visual but if the voltage is the same on both sides then I'll assume it's okay...

The actual install of my relays doesn't match the diagram on the back of the panel so I really don't have a clue which relays might control ignition.

I'm just realizing I need juice going to the starter and the ECU to start the engine. I'm just assuming the ecu's power comes from the "switched" side of the fuse panel -- otherwise, how would you turn the engine off after it's started? (this being an electric engine rather than a mechanical engine...)
banman is offline   Reply With Quote
Old 11-28-2019, 09:16 PM   #6
Bus Nut
 
TheHubbardBus's Avatar
 
Join Date: Apr 2019
Location: Hotzona
Posts: 672
Year: 2003
Coachwork: IC
Chassis: 3800
Engine: Navistar T444e
Rated Cap: 24
You say you have new batteries, is that a change since the last time it ran?


What, exactly, has been touched / changed since the last time it ran?
__________________
-Sharon & Jody
Mr Beefy Short Bus Acquisition & Build Thread
TheHubbardBus is offline   Reply With Quote
Old 11-28-2019, 09:47 PM   #7
Bus Nut
 
banman's Avatar
 
Join Date: Aug 2019
Location: Ohio
Posts: 415
Year: 2002
Coachwork: Thomas
Chassis: Freightliner FS-65
Engine: 7.2L Cat 3126 turbo diesel
Rated Cap: 71 passenger 30,000 gvwr
Quote:
Originally Posted by TheHubbardBus View Post
You say you have new batteries, is that a change since the last time it ran?


What, exactly, has been touched / changed since the last time it ran?
Nope -- bus didn't come with batteries...
New batteries were the single biggest investment in the bus...

Resolved here in similar thread.
http://www.skoolie.net/forums/f38/31...l-q-29431.html
banman is offline   Reply With Quote
Old 11-28-2019, 10:18 PM   #8
Bus Nut
 
TheHubbardBus's Avatar
 
Join Date: Apr 2019
Location: Hotzona
Posts: 672
Year: 2003
Coachwork: IC
Chassis: 3800
Engine: Navistar T444e
Rated Cap: 24
I'm sorry. I didn't realize you resolved your issue. Nor did I realize the last post on this thread was on the 19th! I could have sworn it was the most recent. But I am a little turkey-intoxicated.



Anyway, glad you got it worked out!
__________________
-Sharon & Jody
Mr Beefy Short Bus Acquisition & Build Thread
TheHubbardBus is offline   Reply With Quote
Old 12-02-2019, 10:16 AM   #9
Bus Nut
 
banman's Avatar
 
Join Date: Aug 2019
Location: Ohio
Posts: 415
Year: 2002
Coachwork: Thomas
Chassis: Freightliner FS-65
Engine: 7.2L Cat 3126 turbo diesel
Rated Cap: 71 passenger 30,000 gvwr
And just to follow up with how the juice is flowing --

I still have parasitic drag draining the battery's -- although more slowly...

Since the bus is now at my house I had the luxury of allowing this drain to occur... With the battery's reading a low of 12.6v the bus still fires right up!

So this confirms that my problem was never a low battery charge (before it wouldn't start with battery's at a healthy 12.8v) but the amperage loss of every single wiring connection being a tad grotty...
banman is offline   Reply With Quote
Old 12-02-2019, 12:50 PM   #10
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,246
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
dont most batteries Level off at 12.6? if I saw thuibngs down to 12.2 or so then id suspect a parasitioce drain, but I always thought of a level battery as 12.6
cadillackid is offline   Reply With Quote
Old 12-02-2019, 01:34 PM   #11
Bus Nut
 
banman's Avatar
 
Join Date: Aug 2019
Location: Ohio
Posts: 415
Year: 2002
Coachwork: Thomas
Chassis: Freightliner FS-65
Engine: 7.2L Cat 3126 turbo diesel
Rated Cap: 71 passenger 30,000 gvwr
Quote:
Originally Posted by cadillackid View Post
dont most batteries Level off at 12.6? if I saw thuibngs down to 12.2 or so then id suspect a parasitioce drain, but I always thought of a level battery as 12.6
D'oh! Good point -- another check of the battery chart (there's so many...) shows 12.6v being 90% to 100% charged...

I'll leave the battery's hooked up and see what the rate of discharge continues to be or perhaps I did solve both issues at once...

Breaks over -- back to the grind(ing...)
banman is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 06:11 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×