Jeff, The Vanner you pictured is a monitor that looks at various voltage information and then lights a light on the dash if something exceeds the limits. Several POG members have had that unit fail and give them wrong warnings.
It sounds like your bus has a pair of alternators, one for the house and one for the chassis. What you are concerned with is the chassis alternator. Typically unless the coach has Prevost over the road air, the converter uses a 50DN alternator (12 or 24 volt, depending on the house primary voltage) for the house, and a smaller one, usually around 145 amps, 24 Volt for the chassis.
If your voltage at the Vanner Equalizer checks OK and it goes from the 25.6 (engine off) to around 28 (engine running), and the 12 volt post at the equalizer reads half of the 24 volt post value within 1/2 volt your alternator and regulator are functioning, your voltages are within their limits and it could be an indicator the Vanner monitor has gone bad.
There are three issues that will cause your DDEC to shut the bus down. You know one of them, which is low coolant. The other two are high coolant temperature or low oil pressure. Those shut downs are to protect the engine. If you have been running and the low coolant warning shut you down monitor the coolant level often and very carefully. You may have a leak because as the engine and coolant warms up the coolant expands, but your situation is the reverse of the normal low coolant warning which occurs when the engine is cold and the coolant level is just below the sensor.
Thank you Paul for the heads up on the voltage regulator. I will look there. You are correct about me having had two independent issues. One solved, one still solving. My light came on and stayed on. I wonder if I tried driving with the 24 volt charger on using the generator to power it if that would give me any more clue if the light were to go off. Probably would not tell me anything conclusive but just a thought. My 24 volt chassis alternator is deffinatey working but the regulator (inside?) may very well be the culprit since everything else is checking out. I just got to Camden. Starving for a Maine lobster first and then can test the small Vanner brain.
Steve, thank you for the link to the Vanner manuals. If anyone can tell me a quick way to test the small one I put the photograph on then it might save me from pouring through the manual. I just briefly took the meter to it several hours ago when I stopped for fuel but didn't get any readings and because we wanted to get here to eat I decided not to rush and accidentley short the small Vanner out since the poles are all so close together. I presume it should be fairly self explanatory to put the meter on it and see if I'm getting voltage though it but I honestly don't have any idea what the purpose or function of the small one is to the large one. Both of them however are fairly new.
If you have the 50DN alternator,it has a relay post and if the wire is broken the dash light will be on but the alternator will still be working.I had this problem a few months ago,the terminal wire was poorly crimped and when I touched it it fell apart.
Update: I haven't done anything since my last post ! I don't know how worried I should be about the battery light being on at this point since we've gone about 300 miles with it on and no symptoms (other than the light is on). I don't want to reek havoc with my electrical system and wait until I'm stranded on the road to fix it however. It's bother me. I need to check the small Vanner. But I'm not certain how to test it except poke around with the meter and see if the terminals are showing the voltages they say. We haven't had a lot of down time but this only takes a few minutes so I will buy out the necessary 5 minutes today for sure. There is "Battery High" "Battery Low" and "Balance" terminals on that small Vanner (I have pictured on page 1). What do I look for when putting the meter to these ? I was in a rush the other day and quickly put the meter to the 12 and 24 volt posts and got no reading. I'm not sure if I had a good ground, I was in a rush (just stopping for fuel) and elected to put the meter away and wait until I could take me time which is now.
Jon or anyone- if that small Vanner is bad, and I ignore it temporarily, can it take out any more components (like the large Vanner ?). I have coach breaker (located in the drivers side access panel) that appears to be defective that I was going to pick up in Palinfield NJ Prevost. It goes to the power blinds in the front windshield. If I haven't solved it by the time we get there which is only about another 150 miles, I 'll get their help to poke around with a meter and find the source of the battery light being on.
Jack- My 24 volt alternator just has two posts. One ground and one positive. Is it possible the small wire you refer to that was your culprit is not on mine ? I have a 97 Royal. Is that a converter item or a Prevost wire ?
I also need to get the starter on my Power Tech generator changed. I believe the teeth on it are bad. It's grinding regularly and I want to fix that before I'm left w/o a generator that eventually won't engage at all. I'm able to baby it now and can tap the start button quickly 2 or 3 times and then hold it and it seems to be a method that works to reduce my grind time to a minimum. I'm worried that the longer I wait, the more damage I might be doing to the flywheel. I heard the metal on the starter gear was softer than the metal on the flywheel and would not damage the flywheel that easily but I want to get that fixed ASAP. There wasn't much in the way of suppliers where I've been in New England with the exception of Boston where I probably should have looked for a shop. I'm about to be in and around NYC and NJ and for the generator I'd prefer to avoid the bung hole shafting invoice at Prevost. Does anyone know of a shop you can recommend up in this neck of the woods ? I'm leaving Danbury, CT by noon and going to Whiteplains NY to buy something for work related and then will be going into the city for 4 appointments but I don't think there's going to be a lot of recommendations in NYC.
Is the starter on the back side of the generator ? I fear it is. If it's in the front, I can probably change it myself. If it's in the back, that isn't easy to get to and my generator bay needs to be re-insulated and I have someone that is going to visit me in Florida to help me with removing the gen and doing that job so if the starter is in the back (or requires removal of the generator), I would really like to try and wait on that. We are dry camping on the way home. We are on the move daily and the 12 volt alternator is keeping my healthy battery's up pretty good so I'm not having to start the generator very often. I have a 3,500 watt quiet run gen in the bay as a back up in case the other one get's to the point it finally won't engage.
This is getting too long and I'm supposed to be working on brevity. Ok. Should I fix it or not and if so where ? There. Should I order the starter and have it delivered to Prevost NJ and just get my hands on the part at least ?
Last edited by Jeff Bayley; 05-06-2010 at 08:03 AM.
It is Sunday and I finally got the volt meter to test the small battery monitor made by a Vanner that is relatively new (a couple of years old) on my coach. I downloaded the manual from the manufactures website but it had no specific instructions for testing it. I have a link to the manual below this first link of me testing it in case anyone wants to reference page to which shows some clue as to what my results may indicate. I'm sorry I cannot fully translate them myself to get a conclusive decision on whether it is bad or not.
I believe the first link below will show you the video of me testing it. I am testing it from right to left as you can see and if you go back to the photo I posted on page 1 you can see which terminals say what from a close-up photo that I posted. What I noticed was that almost every reading was almost identical at 28 V and change.
this link takes you to the manual which is only two pages long and shows what each poll should indicate. Three of the polls are supposed to be connected to either buzzers or warning lights (that's my problem my battery light is on) . I have not checked the water level and the batteries yet which is one of the possible culprits. Before I do that to see if anyone could interpret the voltage readings that I took to see if there's something more obvious going on.
based on page 2 of the manual it would appear that my high and low warning light posts are within range. One of them is supposed to go off if it falls below 24 V and the other one is supposed to go off if it goes above 30 volts. I appear to be within range of 28 V unless I'm mistaken. I believe this should also indicate that my voltage regulator on the alternator is working correctly. Conclusions? Suggestions? Go ahead and check the water level in the batteries at this point? I think that one of the things the monitor does is indicate if there is an imbalance in the batteries. That is to say if one of the batteries this notably off from the other three (Coach batteries. I have four.)
I am appending my own posts for yet another issue I need to solve on the road. Where you see pictured below is the plunger that is air operated which moves the passenger seat floor back and forth. Without going into detail am boring you, I need to get a new one as this one has not only broken loose from its mounting (which could be fixed) but the plunger portion which goes in and out is severely bent and an operative. He replaces several years ago after identifying it as the culprit for nearly at Prevost but I cannot recall where I ordered it from. I can see around the unit fairly well but cannot see any markings on it and I don't want to remove it until I have the replacement if I can help it because by removing this it will create a massive air leak causing the coach to fall. They'll make it very easy to get to. I need to drop the front bumper, remove the spare tire, and crawl up under that direction in order to access it and replace it. I don't use a floor that much and may elect just to remove it and splice the two air tubes together in order to make a seal by using a double ended nipple that is the right size.
I was thinking about purchasing a drum all with the cutting wheel on it to remove the plunger which is stuck in the out or extended position so that it could be allowed to retract but I'm not sure if the absence of the full length of the plunger will also cause a leak. Currently, in its damaged and bent status, it is making the coach fall so I suspect that by cutting off the full length of the rod it would probably exasperate the problem. I should probably find a place to work, drop the bumper, remove the spare, and crawl up in the air and get plunger out and connected to tubes to stop the leak. I'm still not sure if there's going to be any OEM information on the plunger to order it. Do any of you recognize the part and can tell me where to order this?
I'm at Lowes. I'm going to drop the bumper, pull the spare and get under to remove this plunger and just cap the two hoses together. I never use the sliding floor anyway and it's just another source for potential air leaks. I'll probably still order a new plunger to have available and on hand in case I sell the coach. After I pull it, I may find the OEM on the device.
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