Master switch no power

daddysgirl · April 24, 2019, 05:09:06 PM

Quote from: richard5933 on April 24, 2019, 04:37:10 PM
Something is definitely wrong with the way the Vanner equalizer is connected then - if it's done correctly both batteries should be used equally. Having one drop like that is an indicator that either the wiring is done wrong or the Vanner has failed.

The left battery draining because of the 12 volt to stud 55 is/was a very common issue for years. I've had several long conversations with MCI techs...and even one with Luke. Sometimes, the techs would use that stud for quick fixes and they never undid the fix. The issue is most likely more wide spread with older coaches, but it happens with the later models as well.

Dreadnought · April 25, 2019, 05:53:14 AM

Quote from: daddysgirl on April 24, 2019, 05:09:06 PM
The left battery draining because of the 12 volt to stud 55 is/was a very common issue for years. I've had several long conversations with MCI techs...and even one with Luke. Sometimes, the techs would use that stud for quick fixes and they never undid the fix. The issue is most likely more wide spread with older coaches, but it happens with the later models as well.

Andrea certainly knows her stuff. Much of it goes over my head, but I'm eager to learn and she always takes the time to explain it to me.

My buses electrical system is a rats nest and gives me nightmares. I'm dreading digging into it, but I know who I'll get advice off of when its time.

Jcparmley · April 25, 2019, 06:47:25 AM

So this morning I checked the batteries and there was no drain overnight. So that is good. I also checked the ECM fuses and all of them looked good. So what I know for sure is:

The Batteries are good
There is power to the 24 volt Bus Bar in the front panel
There is power at the "CC" breaker
No power at the "V" breaker. When bypassing the "v" breaker I do have power at the main dash switch. So I know that breaker is bad.
The Bus will crank when I jump the pins on the back of the main dash switch but it will not turn over.

So today I need to figure out why the bus will crank but not start.

daddysgirl · April 25, 2019, 07:48:07 AM

Hey Markus!
Thank you for the kind words!

JC: What engine do you have?

Do you have anti-theft devices?

Now that the batteries are back, are you getting 24 volts at the starter?

buswarrior · April 25, 2019, 08:01:11 AM

Fuses "look good"?

Nope, test them for current flow.

Looks are for barbie dolls.

Functionality is for busnuts.

Happy coaching!
Buswarrior

Jim Blackwood · April 25, 2019, 08:29:22 AM

Sounds good so far, persistence usually pays off.

We know the engine needs compression and fuel to run, and that's all. So the basics say you aren't getting fuel, assuming it was running before all of this started. Fuel is controlled by the engine controller. So first, make dead certain it is getting power (Is there an indicator light anywhere?)

Also make sure you have pressure on the fuel rail. I'm not a S60 mechanic so I don't know offhand how that's all arranged but the injectors have to get fuel pressure to work and being electronically controlled I'm assuming high pressure fuel is always available to them when the engine is started, so checking that pressure would be a good thing to do.

Next thing you have to deal with are various inhibitor circuits. I can't really help at all there except for the obvious ones like, "is it in gear?" But I do know that it's not unusual for a diesel engine controller to have LED indicator lights for the various inhibitor circuits and if these do that would make the whole process a lot easier. We should be so lucky, right?

Jim

Jcparmley · April 25, 2019, 08:56:34 AM

I have a series 60. I am not sure if there is a theft device. What would I look for?

Quote from: daddysgirl on April 25, 2019, 07:48:07 AM
Hey Markus!
Thank you for the kind words!

JC: What engine do you have?

Do you have anti-theft devices?

Now that the batteries are back, are you getting 24 volts at the starter?

Jcparmley · April 25, 2019, 08:57:36 AM

Great point. I will do that this afternoon.

Quote from: buswarrior on April 25, 2019, 08:01:11 AM
Fuses "look good"?

Nope, test them for current flow.

Looks are for barbie dolls.

Functionality is for busnuts.

Happy coaching!
Buswarrior

Jcparmley · April 25, 2019, 09:00:10 AM

I have power at the starter because when I "bridge" the pins on the master switch on the dash the starter cranks the engine. I don't know if it's a full 24 volts. I will check that this afternoon.

Quote from: daddysgirl on April 25, 2019, 07:48:07 AM
Hey Markus!
Thank you for the kind words!

JC: What engine do you have?

Do you have anti-theft devices?

Now that the batteries are back, are you getting 24 volts at the starter?

Jim Blackwood · April 25, 2019, 11:30:27 AM

You're getting there JC. I worry a little about your wiring methods but just always be sure you can put it back the way it was to start with and you should be mostly Ok. In the end you are likely to find out that you moved something or left something off. I'd say right now you probably need help with the interlocks more than anything else.

And did you ever track down that power drain? That showing up at the same time as not being able to start it seems like too much of a coincidence.

Jim

daddysgirl · April 25, 2019, 03:02:13 PM

Quote from: Jcparmley on April 25, 2019, 08:56:34 AM
I have a series 60. I am not sure if there is a theft device. What would I look for?

Anti theft is something like turning the steplight switch on before you start. I asked about the voltage at the starter because you can have power at the battery and not get 24 volts at the starter. If you don't have enough juice at the starter, it can damage the starter solenoid.
And your coach is different than mine, but there are many posts...same problem. A lot of the time, the neutral switch on the transmission is the culprit, or the gear shift lever isn't set fully in neutral. Those are easily checked before giving yourself nightmares over the wiring. I only know because I gave myself nightmares over wiring a few years ago.

wildbob24 · April 25, 2019, 03:59:46 PM

I'm with Derrick.....it sounds like the ECM is not powering on. The easiest way to tell is the CEL and SEL should light up for about 5 seconds when you turn the bus on and then shut off. If they don't light up, the ECM is not turning on.

Bob

Jcparmley · April 25, 2019, 05:23:45 PM

Hi Jim

Thanks for your help. What wiring methods are you worried about?

. I don't want to do something wrong. I have not tracked down the phantom draw yet. I wanted to get the bus started and moved to a better location. Then I am planning on looking for the draw. I am also going to tape off all the exposed wires that are hanging from the upper storage bays. That way they are not touching and creating a draw.

Quote from: Jim Blackwood on April 25, 2019, 11:30:27 AM
You're getting there JC. I worry a little about your wiring methods but just always be sure you can put it back the way it was to start with and you should be mostly Ok. In the end you are likely to find out that you moved something or left something off. I'd say right now you probably need help with the interlocks more than anything else.

And did you ever track down that power drain? That showing up at the same time as not being able to start it seems like too much of a coincidence.

Jim

Jcparmley · April 25, 2019, 05:28:11 PM

Hi Bob

I am not familiar with the CEL and SEL lights. Where are those located?

Quote from: wildbob24 on April 25, 2019, 03:59:46 PM
I'm with Derrick.....it sounds like the ECM is not powering on. The easiest way to tell is the CEL and SEL should light up for about 5 seconds when you turn the bus on and then shut off. If they don't light up, the ECM is not turning on.

Bob

Jim Blackwood · April 25, 2019, 06:27:39 PM

It's nothing specific JC, but then maybe that is the problem. Electrical systems need a very organized and logical approach. You seem to bounce around quite a lot and I get the mental picture of a bunch of loose wires hanging willy-nilly in no particular order. My apologies if that isn't the case, I realize much of it comes from the DPO's add-ons and is unavoidable at the present. Actually I think you have made great progress and are probably quite near a resolution.

If I understand correctly, you did drive the thing before all this began right? So what exactly happened between then and your discovery that it wouldn't start? If you can nail that down then I think you can isolate the issue. Took the overhead bins and A/C units out right? But what else? Just doing that shouldn't ordinarily keep it from starting. Shorting out the overhead wiring might if it popped the right breaker somehow but that would be going pretty far upstream, probably past lesser breakers that should pop first. I suppose it could happen. You may find those indicator lights on one of the annunciator panels, I don't remember them but I'm still memorizing that stuff. I'll try to take a look tomorrow. Your manual should have everything that's there listed if you can look at those pages. Should be towards the front.

Jim