Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×


Reply
 
Thread Tools Display Modes
 
Old 07-25-2015, 02:34 PM   #1
Mini-Skoolie
 
Join Date: Apr 2015
Posts: 18
Year: 1993
Chassis: Vista
Engine: Dt360
Alternator questions!

Hey yall I've got a couple questions I could use help with. I've got a Thomas international Vista 93

Soo I've noticed lately that my dash volt meter has been reading low at 12v with no load and drops way low to 10 when I run my lights. I'm under the idea that that means my alternator is weak and that is a reading of my batteries depleting voltage. Soooo I took my multimeter and did some prodding to find that ,engine off, my batteries are at 12.7 which is low. And engine running, my front battery is around 13.4 while the other one stays low at 12.5. When I kill the engine they reach an equilibrium of 12.7. What I've learned is that my alternator is not churning out enough voltage to charge them back from starting, is that the right track? The batteries are less than a year old, I got new cables and terminals already. I haven't checked the alternator at is posts because I can't really get to it.


I killed a starter in the past and I'm thinking this is the root cause. I've replaced the starter, the solenoid, gotten new batteries and changed the terminals only to now notice my new batteries being drained.

Does this seem like an alternator issue? Any other way I can troubleshoot the problem? Whats a proper voltage range to both batteries that my alternator should be throwing out while running my engine?


Thanks guys any information helps! I'm always trying to learn more about what I need to know.

---Raven

Raven19988 is offline   Reply With Quote
Old 07-25-2015, 05:06 PM   #2
Bus Crazy
 
opus's Avatar
 
Join Date: May 2010
Location: Montana
Posts: 1,626
Year: 1995
Coachwork: Blue Bird
Chassis: All-American R/E
Engine: 8.3 Cummins
Rated Cap: 72
I would check and double check your grounds before anything else. If that checks out, I say alternator. eBay or Amazon is a good place to find one.
opus is offline   Reply With Quote
Old 07-25-2015, 05:16 PM   #3
Bus Crazy
 
somewhereinusa's Avatar
 
Join Date: Nov 2010
Location: Andrews,Indiana
Posts: 2,430
Year: 1991
Coachwork: Bluebird
Chassis: AARE
Engine: 3116 Cat 250hp
Rated Cap: Just the two of us.
Disconnect the batteries and check individually, sounds like you may have a bad one.
somewhereinusa is offline   Reply With Quote
Old 07-26-2015, 03:37 PM   #4
Mini-Skoolie
 
Join Date: Apr 2015
Posts: 18
Year: 1993
Chassis: Vista
Engine: Dt360
So today I started it up, before I did I checked both batteries and they were at 12.8/7

After starting the front one was at 13.3 with the bus idleing and the other was still at 12.8/7.

I disconnected them from each other and charged them both up off the alternator, which was putting out about 13.4.

If I turned the headlights on it would go down to 13 and if I put the fan on too it would drop to 12.8.

After charging them both up individually I connected them together again and they both read 13.3 while running the engine.

After killing the engine and checking after a little time passed they both read 12.9

Sooo what conclusions can I come too?

What's an acceptable voltage range from my alternator on both batteries while it's running?

Is 13.3 too low of a number, maybe a weak alternator? It seems even running just headlights it can't cover the voltage.

Thanks yall!!!
Raven19988 is offline   Reply With Quote
Old 07-26-2015, 05:29 PM   #5
Bus Crazy
 
roach711's Avatar
 
Join Date: May 2010
Location: Farmington Hills, Mi (Detroit area)
Posts: 1,968
Year: 2000
Coachwork: Eldorado Aerotech 24'
Chassis: Ford E-450 Cutaway Bus
Engine: 7.3L Powerstroke
Rated Cap: 19
12.7 volts is a fully charged battery. With the engine running you should see 13.5 to 14.5 volts at the battery terminals. After the engine has been shut off the batteries should read 13 to 13.5 volts - this is called a surface charge and will bleed off over a few hours down to 12.7 or so. Over a few weeks a normal battery will slowly drain down to 12.5 volts or so.

The true test of battery charge is done with a hydrometer. if one cell reads low that battery needs to be replaced.

Most auto parts stores will test your batteries and alternator for free.

How your batteries are cabled makes a difference too. Proper cabling for a two battery bank looks like this:



Having the positive cable on one battery and the negative (ground) on the other gives both batteries the same current flow so they charge equally. Having both the positive and negative cables on one battery will under charge the second battery.

From here it looks like your system is working though possibly the alternator is a bit weak.
roach711 is offline   Reply With Quote
Old 07-26-2015, 05:51 PM   #6
Mini-Skoolie
 
Join Date: Apr 2015
Posts: 18
Year: 1993
Chassis: Vista
Engine: Dt360
Thank you my batteries are run just like the picture and your info helps me feel like its all good.

My starter will stick randomly and I noticed the low battery voltage and thought it might be the alternator but it seems okay. Ive replaced the terminals, starter, batteries and solenoid and thought maybe it was the alternator that killed my last batteries and starter and is now making the new batteries low thats making my starter stick.

Now im just gonna check everything for a short or weird ground and replace the toggle switch I dunno.

Thanks!!!!!!
Raven19988 is offline   Reply With Quote
Old 07-26-2015, 07:06 PM   #7
Bus Nut
 
Join Date: Dec 2014
Location: Florida
Posts: 584
Year: 1988
Coachwork: Blue Bird
Chassis: I.H.
Engine: DT360
Toggle switch? Is that a battery cut off switch?
HolyBus is offline   Reply With Quote
Old 07-26-2015, 08:51 PM   #8
Mini-Skoolie
 
Join Date: Apr 2015
Posts: 18
Year: 1993
Chassis: Vista
Engine: Dt360
No its a toggle for the starter. I turn my key and the engine wait lightcomea on when it goes off I push down the toggle switch that throws the starter. It was added by the prior owner, I was told there used to be a different switch. It connects between the solenoid and the batteries I think and it could be set up funky.
Raven19988 is offline   Reply With Quote
Old 07-26-2015, 10:57 PM   #9
Moderator
 
crazycal's Avatar
 
Join Date: Feb 2007
Location: NUNYA
Posts: 4,236
Year: 1995
Coachwork: Thomas
Chassis: 3800
Engine: DT408, AT545
Rated Cap: 23 500 gvw
Remember that you have a mechanical engine. Once you start your bus, the only juice you'll need is for lights and radio. You don't have a half dozen computers needing power.
__________________
I'm hungry!

You Gotta Let Me Fly
crazycal is offline   Reply With Quote
Old 11-12-2015, 11:21 AM   #10
Mini-Skoolie
 
Join Date: Apr 2015
Posts: 18
Year: 1993
Chassis: Vista
Engine: Dt360
Sooo it's been some time and in that time I've replaced my alternator, because it finally went caput. It throws out a good voltage.

Now I'm having issues with my starter. The same issues I was having a year ago. Last year I'd throw my starter switch after the wait light goes off and it would not spin and would blow the fuse from the solenoid. Since then I've replaced my batteries, terminals and starter, which mostly solved the problem, thou sometimes It would still have a delay from when I engage the switch to when the starter would spin. I then replaced the solenoid and didn't have to much of an issue for a bit.

Now I'm having the same issue again. I'll turn the key, wait for the light to go off and throw the starter switch and ,just sometimes, nothing will happen until the fuse blows. Usually when I replace the fuse it will work fine after. At this point I've replaced the starter, solenoid, batteries, terminals and my alternator, nd while the issue did mello out it now has the same problem it once had.

Could it be a short in the wires? Maybe this new solenoid is funky already? I'd be a bit annoyed if this new starter got damaged already. I'm gonna poke around and check it all out but any advice would really help.

Thanks yall!!
Raven19988 is offline   Reply With Quote
Old 11-12-2015, 11:33 AM   #11
Bus Geek
 
Join Date: Aug 2011
Location: Stony Plain Alberta Canada
Posts: 2,937
Year: 1992
Coachwork: Bluebird
Chassis: TC2000 FE
Engine: 190hp 5.9 Cummins
Rated Cap: 72
You have a short. We track them with a tool called a amp hound.

The short caused your old alternator to charge at full output till it burned out.

Your new alternator will suffer the same outcome.

Nat
__________________
"Don't argue with stupid people. They will just drag you down to their level, and beat you up with experience."

Patently waiting for the apocalypses to level the playing field in this physiological game of life commonly known as Civilization
nat_ster is offline   Reply With Quote
Old 11-12-2015, 01:10 PM   #12
Mini-Skoolie
 
Join Date: Apr 2015
Posts: 18
Year: 1993
Chassis: Vista
Engine: Dt360
Thanks. Is this something a shop can help me with? You think this is what damaged my last starter as well? It was less than a year old at the time. The prior bus owner put in the toggle switch that's between the batteries and the solenoid and maybe they did something strange.
Raven19988 is offline   Reply With Quote
Old 11-12-2015, 01:18 PM   #13
Bus Geek
 
Join Date: Aug 2011
Location: Stony Plain Alberta Canada
Posts: 2,937
Year: 1992
Coachwork: Bluebird
Chassis: TC2000 FE
Engine: 190hp 5.9 Cummins
Rated Cap: 72
Shop fee's are too expensive.

What I said was I work at a bus shop. The tool we use to find shorts is called a amp hound.



Off name brand units run around $50.

Nat
__________________
"Don't argue with stupid people. They will just drag you down to their level, and beat you up with experience."

Patently waiting for the apocalypses to level the playing field in this physiological game of life commonly known as Civilization
nat_ster is offline   Reply With Quote
Old 11-12-2015, 02:45 PM   #14
Bus Crazy
 
Join Date: Jun 2013
Location: Picton,Ont, Can.
Posts: 1,956
Year: 1997
Coachwork: Bluebird
Chassis: GMC
Engine: Cat 3116
Rated Cap: 72
"The prior bus owner put in the toggle switch that's between the batteries and the solenoid and maybe they did something strange."

Does this statement mean that the starter relay was bypassed and connected straight to the solenoid? I would hope not. If it is that way you might not be getting near enough power for the starter to engage let alone the start solenoid. Check that angle and you may find corrosion on the start relay terminal block. This would explain intermittent starter engagement. Mind you, disconnect the batteries before attempting this, fix the problem then reconnect and start.
__________________
Question everything!
BlackJohn is offline   Reply With Quote
Old 11-12-2015, 03:32 PM   #15
Mini-Skoolie
 
Join Date: Apr 2015
Posts: 18
Year: 1993
Chassis: Vista
Engine: Dt360
There's a little toggle switch on my dash next to the key. When I turn my key this only primes my bus and the wait light comes on. Once the light goes off the little toggle switch is what throws my starter. When I engage the switch the starter *should* spin and the bus start. Sometimes when I throw the switch nothing will happen for a few seconds then the fuse will blow or nothing will happen for a few seconds then the starter will spin.

The prior bus owner told me when I got it that the starter switch used to be outside but he put a new one inside for convenience.

I've only checked a little but I think this toggle switch connects the power from the batteries to my solenoid that's not on the starter but in a side box area.

I've figured in the past that this custom job could have been a little strange so I'm gonna check it out And trace my lines for a short.

Thanks for any info!
Raven19988 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 09:28 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.