Wanderlodge Owners Group  
BuyByeBlueBird.com
Donate

Go Back   Wanderlodge Owners Group > Mechanic's Corner > Electrical

Electrical Discussion of preventative/corrective maintenance and other technical issues regarding your coach's electrical system.

Site Search:
Reply
 
Thread Tools
  #1  
Old 07-02-2018
Mikenjackie's Avatar
Mikenjackie Mikenjackie is offline
Senior Member
 
Join Date: Jul 2012
Location: Full-timing
Posts: 540
Default No DC power!

We're on the way to Hood River for John's rally. This morning when I went to start her up, the engine turned over once, then all DC power was lost; all the circuits that are normally active independent of engine starting, gone
I checked the battery bank, especially ground connections, everything was tight. I'd stupidly left my Fluke at home, so couldn't take any voltage measurements but the Trace inverter, which has a built-in smart battery charger, registered a full battery charge. To check, I used my AC battery charger, it registered full charge, 13.6 volts on the bank. I tried using the AUX BATT switch, that got my DC stuff working, but not enough oomph to start the engine.
I called a mechanic who had no clue, insisted I had a dead battery & tried to jump start from his truck, no joy, of course. Then he wanted to bang on the starter ion case it was stuck, didn't know where it was. He finally found it & told me to try the aux batt start while he whaled on the starter. I went round to the door, & when I opened it the step came out, indicating 12v was back. I turned the key, got all the normal indications & when I tried to start it, she fired up immediately!
So my questions are;
How would trying to start the engine kill the 12v for the rest of the bus?
Why would it suddenly "fix" itself? (the mechanic hadn't touched the starter when power was restored)
What do I do if the same thing happens tomorrow?
Two things; I'm pretty sure the batteries are OK because a few weekends ago, I cleaned up all the terminals, checked & topped p with distilled water, & load checked each battery individually as part of beginning of season maintenance. Also, twice, once before & once after the battery service, when I've tried to start the engine it has made a "chattering" noise as if it can't get through the compression stroke, but using the aux start has always got her running. That wasn't needed the last 3 or 4 starts.
I'm at La Grande for the night, and (hopefully) will be leaving for Hood River in the morning, where I'm sure I'll be able to get pointed in the right direction to fix this thing from the "WOG knowledge base" but any advice just in case she doesn't start tomorrow would be greatly appreciated! (I didn't try starting her once I got here in case I lost all DC again, which would mean no lightying overnight).
If the situation repeats tomorrow, I was thinking I'd take the engine start battery & jumper it to the generator battery. which would hopefully start the engine. But would I have all the other 12v systems back once the engine was running?
Any advice welcome!
__________________
Mike & Jackie Williams
Fruit Heights, UT
385-477-9780, ibmfixer@msn.com
"Retirement Bird" 1997 43WB
"Silver Shadow"1988 PT-40 Concept Coach - Sold!
Reply With Quote
  #2  
Old 07-02-2018
jwood jwood is offline
Senior Member
 
Join Date: Feb 2014
Location: Stratford
Posts: 479
Default

I've had 2 instances where the tin pot looking relays are bad. Once on our 82FC that controlled alternator and other functions. The second on our 94 BMC would shut down the engine and all dash/cab power. It would start back up after a few minutes and everything would perform normally. I would look at those first
__________________
John & Terri Wood
Stratford, Oklahoma
1994 BMC37
Reply With Quote
  #3  
Old 07-03-2018
Dieselbird01's Avatar
Dieselbird01 Dieselbird01 is offline
John Wyatt – Administrator/Moderator
 
Join Date: Feb 2008
Location: Titusville
Posts: 3,897
Default

Quote:
Originally Posted by Mikenjackie View Post
We're on the way to Hood River for John's rally. This morning when I went to start her up, the engine turned over once, then all DC power was lost; all the circuits that are normally active independent of engine starting, gone
I checked the battery bank, especially ground connections, everything was tight. I'd stupidly left my Fluke at home, so couldn't take any voltage measurements but the Trace inverter, which has a built-in smart battery charger, registered a full battery charge. To check, I used my AC battery charger, it registered full charge, 13.6 volts on the bank. I tried using the AUX BATT switch, that got my DC stuff working, but not enough oomph to start the engine.
I called a mechanic who had no clue, insisted I had a dead battery & tried to jump start from his truck, no joy, of course. Then he wanted to bang on the starter ion case it was stuck, didn't know where it was. He finally found it & told me to try the aux batt start while he whaled on the starter. I went round to the door, & when I opened it the step came out, indicating 12v was back. I turned the key, got all the normal indications & when I tried to start it, she fired up immediately!
So my questions are;
How would trying to start the engine kill the 12v for the rest of the bus?
Why would it suddenly "fix" itself? (the mechanic hadn't touched the starter when power was restored)
What do I do if the same thing happens tomorrow?
Two things; I'm pretty sure the batteries are OK because a few weekends ago, I cleaned up all the terminals, checked & topped p with distilled water, & load checked each battery individually as part of beginning of season maintenance. Also, twice, once before & once after the battery service, when I've tried to start the engine it has made a "chattering" noise as if it can't get through the compression stroke, but using the aux start has always got her running. That wasn't needed the last 3 or 4 starts.
I'm at La Grande for the night, and (hopefully) will be leaving for Hood River in the morning, where I'm sure I'll be able to get pointed in the right direction to fix this thing from the "WOG knowledge base" but any advice just in case she doesn't start tomorrow would be greatly appreciated! (I didn't try starting her once I got here in case I lost all DC again, which would mean no lightying overnight).
If the situation repeats tomorrow, I was thinking I'd take the engine start battery & jumper it to the generator battery. which would hopefully start the engine. But would I have all the other 12v systems back once the engine was running?
Any advice welcome!
The fact that you got DC stuff working when you used the Aux Batt switch would seem to indicate that you were not getting any power from the coach batteries.

On some coaches, the 12 volts leaves the coach batteries, goes to a Hot Stud in the engine compartment and then goes to the starter before continuing on to power the rest of the coach. On those coaches, a bad connection at the starter could cause a problem like you’re seeing. Perhaps the mechanic touched those wires while he was looking for the starter?
__________________
John Wyatt
Titusville, Florida
1991 40' WLWB-WTB
Body Number F095567
My Location: http://www.bbirdmaps.com/user1.cfm?user=4

1991 40' WB ...From 2008 - Present
1984 ½ PT-36 .From 2000 - 2008
1973 FC-31 .....From 1991 - 2001
Reply With Quote
  #4  
Old 07-03-2018
Mikenjackie's Avatar
Mikenjackie Mikenjackie is offline
Senior Member
 
Join Date: Jul 2012
Location: Full-timing
Posts: 540
Default

By "hot stud", do you mean a screw terminal with 3 or 4 wires attached? (cos I'm sure you're not referring to me). There IS one of those, & it has a crimp connection on the wire going to it from the battery; I'm wondering if there's an intermittent open circuit there. I'll check it out in the morning if it does the same thing again...thanks for the info!
__________________
Mike & Jackie Williams
Fruit Heights, UT
385-477-9780, ibmfixer@msn.com
"Retirement Bird" 1997 43WB
"Silver Shadow"1988 PT-40 Concept Coach - Sold!
Reply With Quote
  #5  
Old 07-03-2018
gcyeaw's Avatar
gcyeaw gcyeaw is offline
Gardner
 
Join Date: Dec 2007
Location: Ridgewood
Posts: 8,850
Default

Buy a backup voltmeter so you can check things 'when' it happens again.
__________________
Gardner Yeaw
86 PT-36 Golden Memories
83FC35 SB $IXTEEN TON$ SOLD
78 FC 33 Happinest (Sold)
Ridgewood, New Jersey
Reply With Quote
  #6  
Old 07-03-2018
irmagoo's Avatar
irmagoo irmagoo is offline
Senior Member
 
Join Date: Jul 2010
Location: washington
Posts: 2,565
Default

i think modestly priced meter to stay in coach is a good idea but i would check and clean all battery connection including grounds also pay close attention to the crimp on ends they can have corrosion inside due to age, salt what ever. i try to stay on top of these things things if you see the green blueish corrosion creeping out crimp ends they need replaced . best of luck mike
__________________
mike mcgraugh
2003 LXI
"Blacktop Gyspy"
even a blind squirrel finds a nut once in awhile
washington Il.
Reply With Quote
  #7  
Old 07-12-2018
Mikenjackie's Avatar
Mikenjackie Mikenjackie is offline
Senior Member
 
Join Date: Jul 2012
Location: Full-timing
Posts: 540
Default

Well, after a few days, probably 8 flawless engine starts, it happened again this morning; engine turned over once, then total loss of DC power. I re-tightened all the battery terminals, the RV park owner tried his high-amperage engine start power pack, first on the battery bank, then on the genny battery while I tried the combiner switch. After many choice swearwords, I looked under the bus at the starter; all the wires seemed OK, but there is a little doo-hicky, looks like an inverted bell, just kerbside of the starter. It had oil all over it, only reason I noticed it was that I got oil all over my arm brushing against it. I wiped it clean, it has an electrical connection on the bottom, went back inside to clean up...and all of a sudden I had DC back again! Engine fired up right away.

So, my question is, what is it? Seems whatever it is, it's the culprit. This is a view looking up from underneath.
Attached Thumbnails
Click image for larger version

Name:	IMG_0897.jpg
Views:	94
Size:	198.6 KB
ID:	56473  
__________________
Mike & Jackie Williams
Fruit Heights, UT
385-477-9780, ibmfixer@msn.com
"Retirement Bird" 1997 43WB
"Silver Shadow"1988 PT-40 Concept Coach - Sold!
Reply With Quote
  #8  
Old 07-13-2018
Dieselbird01's Avatar
Dieselbird01 Dieselbird01 is offline
John Wyatt – Administrator/Moderator
 
Join Date: Feb 2008
Location: Titusville
Posts: 3,897
Default

Quote:
Originally Posted by Mikenjackie View Post
Well, after a few days, probably 8 flawless engine starts, it happened again this morning; engine turned over once, then total loss of DC power. I re-tightened all the battery terminals, the RV park owner tried his high-amperage engine start power pack, first on the battery bank, then on the genny battery while I tried the combiner switch. After many choice swearwords, I looked under the bus at the starter; all the wires seemed OK, but there is a little doo-hicky, looks like an inverted bell, just kerbside of the starter. It had oil all over it, only reason I noticed it was that I got oil all over my arm brushing against it. I wiped it clean, it has an electrical connection on the bottom, went back inside to clean up...and all of a sudden I had DC back again! Engine fired up right away.

So, my question is, what is it? Seems whatever it is, it's the culprit. This is a view looking up from underneath.
Looks like an oil pressure sender - maybe for the dash gauge?
__________________
John Wyatt
Titusville, Florida
1991 40' WLWB-WTB
Body Number F095567
My Location: http://www.bbirdmaps.com/user1.cfm?user=4

1991 40' WB ...From 2008 - Present
1984 ½ PT-36 .From 2000 - 2008
1973 FC-31 .....From 1991 - 2001
Reply With Quote
  #9  
Old 07-13-2018
Rick's Avatar
Rick Rick is offline
Senior Member
 
Join Date: May 2009
Location: Bellefonte
Posts: 13,226
Default

Thats what I think also. That isnt you DC power problem. Check the large nut on the starter.
__________________
Rick Shawver
1SG Ret
2000 LX
Vise Grips
Bellefonte, AR
F127656
Reply With Quote
  #10  
Old 07-13-2018
Dieselbird01's Avatar
Dieselbird01 Dieselbird01 is offline
John Wyatt – Administrator/Moderator
 
Join Date: Feb 2008
Location: Titusville
Posts: 3,897
Default

Quote:
Originally Posted by Rick View Post
Thats what I think also. That isnt you DC power problem. Check the large nut on the starter.
Yep, I tried to point out that connection in post #3 as well.
__________________
John Wyatt
Titusville, Florida
1991 40' WLWB-WTB
Body Number F095567
My Location: http://www.bbirdmaps.com/user1.cfm?user=4

1991 40' WB ...From 2008 - Present
1984 ½ PT-36 .From 2000 - 2008
1973 FC-31 .....From 1991 - 2001
Reply With Quote
Reply

Bookmarks

Thread Tools

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
One leg of power with full power at Breaker 4freedomrider Electrical 8 05-14-2017 07:18 PM
Power input on PT 40 (shore power) doctorlock Electrical 4 08-16-2016 06:58 AM
Wind, hail, rain, trees and power poles down and power outage....Powertech NO VOLTAGE iamflagman Generators 22 07-06-2016 07:12 PM
No 12 power left front power center Jeff Electrical 21 03-02-2013 09:22 AM
No ac power and no blower on Power Tech drilldoc Generators 33 07-10-2011 08:18 AM

Web Search:

All times are GMT -4. The time now is 01:28 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.