Need Alternator Near Harrisburg, PA

luvrbus · October 06, 2014, 07:17:03 AM

Seems like the Vanner is working if you have a 12.3 reading on one battery they pickup any thing below 12 v and try to equalize the batteries the purpose of Vanner is to draw the loads equal from the batteries I thought

I doubt your engine and transmission run through the Vanner

eagle19952 · October 06, 2014, 08:33:49 AM

suspecting and knowing are very different.
Surely you would know before replacing.

Lostranger · October 06, 2014, 10:16:35 AM

I'm going to limp home with the help of a battery charger. There I can complete troubleshooting the issue. I've been in touch with someone experienced in Gillig electrics, and I'm following his advice.

luvrbus · October 06, 2014, 11:57:36 AM

Good a person does need experience on that system,now is the time for you to start locating a person that is up on the DT 466 engine you need it when the EGR takes out number 4 and 5 cylinders

I have one here now that is a weak point on that engine fwiw if you have the EGR

Lostranger · October 08, 2014, 09:32:24 AM

Made it back to home base Wednesday at noon. Rain forced us off road yesterday afternoon near Wytheville, VA. Ran a trickle charger overnight from our house system. Started fine this morning.

Going to Atlanta tomorrow to pick up a used Vanner and a good alternator. I'm thankful for the help of a list member who lives in that area.

Jim H

Oonrahnjay · October 09, 2014, 04:47:14 AM

Quote from: Lostranger on October 08, 2014, 09:32:24 AMMade it back to home base Wednesday at noon. Rain forced us off road yesterday afternoon near Wytheville, VA. Ran a trickle charger overnight from our house system. Started fine this morning.

Going to Atlanta tomorrow to pick up a used Vanner and a good alternator. I'm thankful for the help of a list member who lives in that area.

Jim H

Good news! Drop by Charlotte again sometime!

Homegrowndiesel · October 09, 2014, 09:59:31 PM

Bad battery? I think the engine and trans do work from the vanner on that unit, ,? I had a shorted battery that pulled so hard on the alternator that it whined. Hope your fix is that easy. Inquiring minds would like to know.

Lostranger · October 10, 2014, 02:29:21 AM

Batteries both take full charge, but I've not yet load tested them. Alternator still putting out 28.1v, and the noise has quit since I got batteries charged. It's still leaking.

I drove to Atlanta yesterday and came back with good used alternator and Vanner which has not been tested. I'll know more in a few hours.

Jim H

Oonrahnjay · October 10, 2014, 05:12:52 AM

Quote from: Homegrowndiesel on October 09, 2014, 09:59:31 PMBad battery? I think the engine and trans do work from the vanner on that unit, ,?

Yes, at least some Gillig buses are 24V for the charging system but the Electronic Control Modules (aka electronic computers) for the engine and transmission are 12V and run off the 12V supply from the Vanner. Therefore, no Vanner (or Vanner not working properly) means that engine or transmission doesn't work. I don't know if this applies to Jim's bus or not. The fact that he was able to charge the batteries with a non-engine-driven charger and successfully drive it should mean that the Vanner is working at least well enough to power the ECMs -- but maybe he's not 100% reliant on the Vanner anyway.
If I had to guess -- and it would only be a WAIG! -- I'd guess that it is a bad alternator that's making some power but power that's funky enough to throw off the function of the Vanner. My guess, changing the alternator will show him that the existing Vanner is OK, but it also wouldn't surprise me if maybe his existing Vanner was damaged by the poor power characteristics of the bad alternator so that it's only working marginally and he may have to replace it too.
But this is all guessing - Jim has the bus, the troubleshooting equipment, spare parts -- he'll run down the problems and let us know exactly how it turns out.

Still wishing you good luck, Jim!

Bruce H, NC USA

luvrbus · October 10, 2014, 05:33:21 AM

I hope he gets the problem solved the ECM on the series 40 is a complicated little item like Bruce I don't see it running if the Vanner is bad if it is run through the Vanner on his year model the ECM controls the intake and exhaust valves

Lostranger · October 10, 2014, 03:58:01 PM

All is resolved. It was a bad Vanner. I'm posting details under the trip section of this BB. My thread is called Music Weekend in PA.

Thanks to all of you who offered helpful information and encouragement. Thanks to the rest of you for your participation.

I especially appreciate the post on testing a Vanner without an ammeter.

Click over to the trip section to read details if you're interested.

Jim H

bevans6 · October 11, 2014, 07:06:57 AM

The inside of a Vanner is basically a switching power supply that runs off of the 24 volt input, an autotransformer to create the half-voltage output and a precision pair of resistors to create a voltage divider that controls the output voltage at 50% of the input. It puts out sufficient current on the 12V leg to force the batteries to be at an equal voltage. If it doesn't need to put out any current, it doesn't draw any current at the 24 volt input. If it does need to put out current it pulls it in at 24 volts and puts it out at 12 volts. That is how they get their "series-parallel" effect on the batteries. The two 12v batteries are obviously in series to create the 24 volt pair, but they both supply power to the 12v terminal as if they were in parallel.

If you have a failing battery and the Vanner is connected, if it's the low side of the pair (the 0 - 12v battery) the Vanner will kill both batteries trying to keep it up to 50% of the pair's voltage, whatever that is.

Brian