Master switch no power

[buswarrior]

First issue in my mind is these phantom GPS devices.

Get after the PO and get some Intel on the intended range of function. Does it shut down the ignition? Is there a start sequence for security purposes?

You can't mix apples and oranges. Someone has monkeyed the wiring, you need to find out what was supposed to be doing, before you try to figure out what it isn't doing.

Without the proper schematic, and then work backwards on what MCI built, and trace to where the add-ons are spliced in, and see where those wires lead to, we're all just filling the internet with typing conjecture.

Sloppy wiring in a fleet setting is not unusual....

Happy coaching!
Buswarrior

[Jcparmley]

I don't understand.   This morning I went out to check on the bus and the left battery was at 3.5 volts.  Monday I put two new batteries in and put a shut off switch on the main ground cable.  With the main ground shut off how can the batter run down.  Everything should be shut off if it can't find the ground, correct?  also, why would the left battery be drained and not the right batter if they were connected, as they were?  I am so frustrated.

[Jcparmley]

The PO wasn't the fleet company.  He purchased from the fleet company and has said he never opened up the dash.  Looking up the devices might give me info on how it was wired.  Perhaps I can find a schematic for the individual devices.  That's a great idea.  I will let you all know what I find.

First issue in my mind is these phantom GPS devices.

Get after the PO and get some Intel on the intended range of function. Does it shut down the ignition? Is there a start sequence for security purposes?

You can't mix apples and oranges. Someone has monkeyed the wiring, you need to find out what was supposed to be doing, before you try to figure out what it isn't doing.

Without the proper schematic, and then work backwards on what MCI built, and trace to where the add-ons are spliced in, and see where those wires lead to, we're all just filling the internet with typing conjecture.

Sloppy wiring in a fleet setting is not unusual....

Happy coaching!
Buswarrior

[richard5933]

Wasn't your Vanner still connected when you shut off that ground conductor shut-off?

[Jcparmley]

I'm not sure.  I thought if I disconnected the main ground that would turn everything off including the vanner.  I must be wrong and something is draining the battery.  The wired thing is that it only drained one battery.

Wasn't your Vanner still connected when you shut off that ground conductor shut-off?

[richard5933]

I'm not sure.  I thought if I disconnected the main ground that would turn everything off including the vanner.  I must be wrong and something is draining the battery.  The wired thing is that it only drained one battery.

If your Vanner's 12v connection to the middle of the 24v bank is still in place, and there is a 12v load someone tied to that 12v Vanner output, my guess is that the ground on the 24v load is what drained your battery.

Why just one battery? Because the ground cable disconnect took the other one out of system, making it impossible for the Vanner to drain both equally.

Did you confirm that nothing is pulling a load from the Vanner's 12v output?

[Jcparmley]

No I haven't checked the load on the vanner.  How might I do that? 

If your Vanner's 12v connection to the middle of the 24v bank is still in place, and there is a 12v load someone tied to that 12v Vanner output, my guess is that the ground on the 24v load is what drained your battery.

Why just one battery? Because the ground cable disconnect took the other one out of system, making it impossible for the Vanner to drain both equally.

Did you confirm that nothing is pulling a load from the Vanner's 12v output?

[buswarrior]

Put your disconnects in the positive feeds. Stick to traditional methods...

For busnut use, ALL loads go beyond the shut off switches.

The equalizer may stay inside the shut off.

Charge each 12 volt battery separately to full charge to get this mess reversed.

Ground isn't ground when you have a centre tapped pair of 12 volt batteries making 24 volts with a Vanner battery equilizer involved.

I wonder if we could conjure up a FIRE scenario, if the correct sequence of events were followed with the coach in this configuration... power travelling "backwards" on wires not intended for the load... traditional methods cover off so many obscure failure points...

Anyway... welcome to 24 volts!

Happy coaching!
Buswarrior

[buswarrior]

Your Vanner worked fine.

Get rid of that ground side switch, charge batteries separately, get all the loads onto switches, leave the vanner alone.

You have better things to frustrate you, than wasting time checking an equalizer that you set up to kill a battery.

Self inflicted wound.

Back to getting this to run...

Happy coaching!
Buswarrior

[Jcparmley]

Ok, so I disconnected the two batteries from each other and am charging them up again so I can begin testing again.  Your suggestion is to take off the shut off switch off the main ground and put it on the positive on each battery between the positive and the main 24/12 volt switch?  Is that correct?

Put your disconnects in the positive feeds. Stick to traditional methods...

For busnut use, ALL loads go beyond the shut off switches.

The equalizer may stay inside the shut off.

Charge each 12 volt battery separately to full charge to get this mess reversed.

Ground isn't ground when you have a centre tapped pair of 12 volt batteries making 24 volts with a Vanner battery equilizer involved.

I wonder if we could conjure up a FIRE scenario, if the correct sequence of events were followed with the coach in this configuration... power travelling "backwards" on wires not intended for the load... traditional methods cover off so many obscure failure points...

Anyway... welcome to 24 volts!

Happy coaching!
Buswarrior

[buswarrior]

No

Look at it from the other side.

You have 24 volt loads, and 12 volt loads.

All the 24 goes to the coach's current shut off, and the big 24 volt battery cable goes to the other side.

The 12 volt loads are often smaller wires and attach in disorganized fashion wherever the last boob attached them, either the centre of the 2 batteries, sometimes to the vanner posts...

You typically have to establish your own collection point for all of the 12 volts stuff, switch it, and then feed the switch from the centre of the batteries. The Vanner post that connects to the centre is an acceptable place too.

The 2 batteries and the vanner stay connected together, the switches isolate everything else from that "package"

But, this is fiddling around.

The coach needs to RUN...

Happy coaching!
Buswarrior

[skihor]

I had a 40 amp Vanner. Left it connected always. I could leave my battery disconnect on while traveling. I would shut the main disconnect of for extended non-use. I changed to an 80 amp Vanner. My batteries would be dead in 12 hours. I had to disconnect the Vanner every eve when traveling. I re-installed the smaller Vanner and all is well again. So I guess I had a bad Vanner for unknown reasons.

[buswarrior]

Skihor raises an issue.

Vanner battery equalizer has a prescribed order in which to connect and disconnect the cables.

Some have ignored this, and saw no symptoms of failure.

Others have dead Vanners...

Vanner is used to protect the battery set from the imbalance of taking 12 volts out of the low side battery, and nothing from the high side. Add in charging, one battery doesn't get charged enough, the other gets charged too much...

But for the moment, we have to GET THAT COACH TO RUN...

Put a switch on the 12 volt loads, and completely disconnect the vanner until the coach is running, then we can go back and mess around...

Nobody happy without progress, this is how the support for the project falls flat...

Happy coaching!
Buswarrior

[Jim Blackwood]

This has all been pretty hodge-podge, jumping back and forth all around the bus, and that's not the way to troubleshoot electrical problems. It takes a logical and systematic approach. What do you know for certain? Have you confirmed that all batteries, with the terminals disconnected from anything at all, fully charged, will stay that way overnight? If you haven't, then do that first. Next, connect your grounds. Now go get a small light bulb and connect it between the battery + post (for each one) and the cable. Does it light up? Make sure it works too by connecting it across the battery. If it lights up any at all, or if you see the slightest spark, begin there. An LED works great for this test but you have to be sure and observe correct polarity. If you're making up a test light you can solder in two LED bulbs back to back in opposite directions (usually with a resistor) and better yet make them different colors. A buzzer is often helpful.

You should confirm what you already know, the one battery that drains down lights up between the battery post and the cable. So follow that out. Where does it go next? Test that. Where does it branch? Determine which way the current is going. This is simple and you can do it easily, you just need to quit looking all around and hoping to find the problem by observation. You can't see electricity, and you usually can't see where it leaks out. Unless you get smoke.

Jim

[Jcparmley]

Good point.  I am charging the batteries right now independently of one another.  I also switched my shut off switches on the positive sides of the battery before it goes to the master switch.  Before I disconnected the battery I checked the "V" breakers in the front j box.  I had no power so I believe that breaker is bad.  So I bypassed the breaker with a number and sat in the drivers seat with my voltmeter to see if the master switch was getting any power.  While testing my positive lead on the voltmeter touched two pins on the back of the main power switch and everything lit up and the traditional beeping low air began.  So I know for sure the "V" breaker is weak.  I am still trying to find what wires go to what pins on the back of the main dash switch.  I have some wires that were pulled out and I am trying to figure out what pin they go to. 

As far as the parasitic draw I haven't figured that out yet.  I am trying to get the beast started so I can move the bus to a better place to work on it.  Then I will try to figure out what is drawing the battery down.