Plenty of times in my life, I've had cars that have alternators go bad and result in NO voltage... but I've never had the opposite..
When taking off onto an interstate, my voltage meter is jumping from 28 to 32 volts. The needle just waves at me (28 to 32 to 28 to 32 to 28) until I let off the throttle, then it returns to a steady 28. So if I baby it, there is no problem. Then... if I'm going over 65 miles and hour and hit the brake it will also do it. For example if I'm coming down a hill at 65mph or above, and hit the brakes, it will wave at me again, but if I let off the brakes and coast, it will return to a steady 28. The only other time I can get it to do it is if I do a hard down shift. I'm certain it's not simply a gauge issue because I can hear the driver air conditioner fans speeding up and slowing down as the needle waves at me.
Any thoughts, comments, suggestions?
Something big and drawing a huge overload...like a motor... shorting on one portion of rotation... maybe the alternator itself...
It's losing the ground between the alternator and voltage regulator sounds like to me
Could you describe to me what a voltage regulator looks like? I will check for loose connections.
Bryan -
Which coach are you talking about? The Prevost or the GMC?
Not sure if GM kept the voltage regulator in the same spot on the 4107s as they did on the 4106s, but if they did, it's on the back (axle) wall of the rear baggage bin. A vertically-ribbed black box approximately 4"x9" with a big screwdriver slot in the middle. (Maybe they moved it to the battery compartment? Or to the rear electrical compartment behind the RR wheel?) You'll have to poke around until you find it. When you do, make sure you disconnect the chassis batteries so you don't spark any surprises while checking connections!
Can't help on the where the regulator is on a Prevost, unfortunately, but it would look similar to the GM's.
FWIW & HTH. . .
;)
Thank you guys! I'm sorry I probably should have specified... this post for for the Prevost. Thanks for all your input and suggestions!
Dash gauge?
Use your multimeter to confirm there really is a problem.
One of the biggest Chhicken Littles for a busnut is a dash gauge suggesting the sky is falling...
happy coaching!
buswarrior
Whatever the cause, bad regulator, bad ground, etc. it is an issue that cannot be ignored. It can lead to expensive problems.
If the coach is equipped with a Vanner monitor I am surprised it wasn't lighting up lights on the dash.
If you have one of the old style a big black box with cooling fins spend the bucks and buy the 1941463 regulator they have voltage over protection,short circuit protection and a automatic shut down with a reset button,the latter is something needed with a friggn Vanner.The regulator should be in the battery compartment along with the Vanner
Either of these the regulator?
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fuploads.tapatalk-cdn.com%2F20160717%2F1b9dcab6eaa5449bfde1dfc6a3198b2d.jpg&hash=b8282b6b52cab4bbaa12c16f083978d69ad363b9)
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fuploads.tapatalk-cdn.com%2F20160717%2F2193bd2a5116a0b885f2c777026437d1.jpg&hash=830f9d4e4ba83f037aa570c91234b921a5e76afb)
Nope. Thats the vanner and control box
Nope it will have 4 terminals either will be 4 inches wide x 8 inches long with cooling fins or a gray box 4x4x1 with 4 terminals mounted below the main circuit breakers on the left side
https://vimeo.com/175157275 (https://vimeo.com/175157275)
I took a short video in my previous post. Do you see the regulator?
Quote from: Bryan on July 17, 2016, 04:35:37 PM
I took a short video in my previous post. Do you see the regulator?
no
What alternator is on the engine ? if you have a Niehoff (Prestolite) the regulator is on the alternator attached by 4 bolts on the top of the alternator
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fuploads.tapatalk-cdn.com%2F20160718%2F52c046927f0ff8d6641df9ed791cf3e3.jpg&hash=9338671d37ee391bf012aa6dc209bfaf04034550)(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fuploads.tapatalk-cdn.com%2F20160718%2F5ad85925b7c7c19cb92cfafe99c941f0.jpg&hash=49351fc0cbb3a7a2698338f61ebba153ffcf229c)
A couple pics of alternator
Does the bus have dual alternators ? that looks like a house battery bank Niehoff alternator
I'm not seeing anything else that looks like an alternator
Also, when I called Prevost to get a price on alternator, they only mentioned one so I'm thinking there is only one.
What alternator make and model did Prevost quote a price on ?
Alternator 562235D 845.46
Regulator 064717 367.76
Bryan,I don't know what going there on all the 1996 Prevost I been around with the 60 series have a oil cooled Delco 50N alternator mounted on the engine driven by a serpentine belt not the V belts.That is a air cooled alternator maybe a owners change ? or a converter deal I don't know
okay... so the 562235D Alternator is the one I have or the 50N that is mounted on the engine? Maybe Prevost is giving me the wrong one too?
Bryan, the 562235D is a 270 amp Delco oil cooled alternator belt driven,did they quote over 1k exchange ? the one in the photo is not a 50D Delco it's probably a 140 to 180 amps, just guessing maybe the 50DN quit and the PO didn't want the expense of replacing it and that is the reason you cannot find the regulator where it supposed to be
okay, maybe that is the case.... not sure what you mean by 1k exchange...
I'm really trying to get my ducks in a row before taking it to a shop. I'm sure they can tell me about the alternator and regulator... it sounds to me that you may be right in that it was changed out for a cheaper alternator...
so would you agree that my problem has to be from only one of these 3 items... 1)ground 2)alternator 3)regulator... or are there other possibilities?
last question... if I were to buy the recommended alternator and regulator and put it back to factory specs... how much labor would go into this?
Thanks for your help! ;D
Did Prevost ask for 1000 bucks exchange for the alternator.Look on the right side of the engine to see if the cradle is still there that is a big expense the 2 oil lines and belts are cheap
no they did not ask for 1000 bucks in exchange... however I told them I wasn't purchasing it yet, just price checking, but it seems they would have at least mentioned it right?
I will run outside and look for a cradle... not totally sure what I"m looking for but something that would hold an alternator and looks empty LOL? ... how much are cradles?
I just checked for the model number you posted Prevost wants $1099.00 exchange for the alternator and $500.00 for the regulator number fwiw
I didn't see a cradle, about how much are those? And about how much labor is involved in changing back to stock?
when you say exchange... you mean $1,099.00 plus send them my alternator correct?
that's strange because I spoke with someone on the phone at Prevost on friday and they said
Alternator 562235D 845.46
Regulator 064717 367.76
$1099.00 till you return the old alternator,$500 till you return the regulator is what my price sheet is showing,they maybe cheaper now Prevost does that to move old stock but there will be a core charge if you don't have the right alternator and regulator to exchange
do you have over the road air conditioner ?
no ... you don't need, nor want the 1000$ alternator.
and you don't need exchange with freight. any reputable Alternator shop can solve you needs for under 500$.
i get mine here
http://www.arcomarine.com/xhtml/More_about_ARCO_Marine.html (http://www.arcomarine.com/xhtml/More_about_ARCO_Marine.html)
no I don't have over the road air... all air units are powered by generator.
I wish I could find the regulator LOL.
Quote from: Bryan on July 17, 2016, 09:25:30 PM
no I don't have over the road air... all air units are powered by generator.
I wish I could find the regulator LOL.
The regulator for the alternator in the photo is integrated in the alternator that is where you will find it.That should work if you can figure out if they have the house system and chassis system isolated from each other using the 1 alternator
Ok gotcha! I have recropped the picture... Is this this regulator? And does this come with a new alternator or are these 2 separate pieces to purchase?
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fuploads.tapatalk-cdn.com%2F20160718%2Feef937ecd6421c2b161cb30853853dc9.jpg&hash=651c45d42cc423c929bec8f108a1de594f9e0db2)
If you had time available, this looks like the 25si delco and may have to be removed after some battery disconnections.
Then taken to a local alternator rebuilder if available, hopefully. I believe it would take something like this as reference if "just" the
http://www.ebay.com/itm/B676-NOS-24-Volt-Neg-Ground-Reg-for-Delco-Alt-/261886701792?_trksid=p2352135.l4275 (http://www.ebay.com/itm/B676-NOS-24-Volt-Neg-Ground-Reg-for-Delco-Alt-/261886701792?_trksid=p2352135.l4275)
24v regulator problem but without more checks and tools it would be best having someone do some more checks.
finding the regulator is not really going to help you.. I am not a good word person ..but based on what I read here...you need to find a diagnostician and bite the bullet here.
if they would ..CarQuest could analyze your situation in about five minutes......and any shop could remedy it in 30-60 minutes.
Anyone who can't identify a regulator needs to not be the one solving the problem.
I said before ...is the center axis of the alternator magnetic ?
If not and knowing you have an integral regulator...99.9999999999999999% likely you need and alternator.
BUT... have you even checked for a loose/slipping belt ?
Who converted the coach? From what I saw that alternator is non serviceable regarding the voltage regulator which is internal to the alternator.
I wanna say "ECM"??? Did the conversion
Never heard of that converter, but that does not matter. Without full coach AC the typical conversion uses a 50DN alternator for house purposes and goes to a smaller 145 amp alternator as show for chassis purposes. If that is the only alternator you have I admit to being surprised because that suggests whoever converted it may have planned on running a generator and keeping the coach house batteries charged via the inverters.
I seriously doubt if the house and chassis systems are merged, but are they? And then when are you seeing 32 volts? When driving or when the generator is running?
It's going to be interesting when he starts digging around I bet the 2 systems are charged with the 1 alternator how they are separated is going to be a guessing game
The generator that powers the house portion of the bus has it's own alternator.
I hope your not stranded, if so please say so.
That alternator in the pic I'm pretty darn sure is 50 or 75 amp and just for basic charging 24v engine and the running of the bus.
I need to ask what else is using its power?
Far as buying a rebuilt one on the intranet I haven't a problem with 250.00 probably, though its the shipping and returning core that can be tough.
Do the batteries stink like acid and are they sweating or leaking from boiling over from high charge, possibly they have been hot and or have warped sides.
I would get the 17 dollar DVOM with min-max ability and hook it up to battery and verify a few times.
That's 40 + feet of wire to gauges so checking in the rear carefully is called for.
good luck :)
Floyd
If he has a factory motorhome shell from Prevost they used the 270 amp 50D for house battery charging and a 140 amp for the chassis. I don't know what he has but the part numbers he posted Prevost was going to sell him a 50D they used his serial number and that is what it left Canada with not the setup he has now
Quote from: Bryan on July 18, 2016, 01:55:03 PMThe generator that powers the house portion of the bus has it's own alternator.
Bryan, let's be careful here. I think you're talking about the separate battery for the alternator. In that case (and if you have one, it's a good thing because it will be independent of the other batteries in the bus - if your house and start batteries are dead when you're boondocking, you can start the generator, have electricity to run "house" functions and also charge up the start batteries so you can get the engine going without a service call), there is a battery charge function in the generator assembly that keeps that one (on my bus, it's a separate small Group 29 battery - I think - about the size of a car battery, mounted right next to the generator housing itself.
Don't let this one confuse things, it's entirely on it's own and the chassis (starting) battery system and the house (camping) battery system will have nothing to do with it and it can't cause problems with the alternator or charging system on your bus engine.
HTH, BH
Bryan, have you confirmed the voltage using a multi-meter yet?
If all this wild goose chasing is due to a faulty dash gauge on an old bus...
happy coaching!
buswarrior
The only Prevost experience I have is from when I was looking at buying a 1996. It had a large 24v alternator for the coach and a 12v alternation mounted like the one in your picture for the house. Have you tested the voltage from the alternator to determine which system it is for?
Newer bus doesn't mean less problems ,huh Bryan??? I have sure found this out also!!
hey guys! Sorry for the delayed response, I have been out of town. The coach is now at a shop, and thru some research, it IS in fact a 24volt alternator, and it is not putting out proper voltage.. .I'm now waiting on the shop to send it to be rebuilt.
The crazy thing about it is... the part number on the alternator is for a 12v... thru research I have learned that the converter had a 12v rebuilt to be a 24v.