12V Electrical Issues - It's Complicated

I still have the issue with the generator not starting, no clicks, no nothing, like a relay or something being open.

I really cannot see where that circuit starts and what might be in that circuit, including something on the transfer switch board, that might have gone out.

Any general thoughts on where to start testing?

skyking4ar2 said:

I still have the issue with the generator not starting, no clicks, no nothing, like a relay or something being open.

I really cannot see where that circuit starts and what might be in that circuit, including something on the transfer switch board, that might have gone out.

Any general thoughts on where to start testing?

Click to expand...

I don't think you have mentioned which model generator you have.

Sorry, Tom, it is an Onan 7.5 kw diesel.

http://truckroadservice.com/barth_attachments/682105772_Onan_DKD_Service_Manual.pdf

This is a link to a service manual that might help you. It has fairly detailed trouble shooting steps. If this is not your model then Google should be able to help you find the one that is.

When my 4.0 was on the fritz I was able to get it going using the service manual trouble shooting section of my manual.

Tom,

If nothing else, that manual will be a good primer on how the generator system works, which I do not understand at this point. I am electrically challenged, but I can check off a troubleshooting tree easily enough.

Since the generator was running fine, then just would even begin to start just a little while later, I feel certain there is just a failed component somewhere that has to be fixed or a wire came loose.

Thanks!

Kim

skyking4ar2 said:

I still have the issue with the generator not starting, no clicks, no nothing, like a relay or something being open.

I really cannot see where that circuit starts and what might be in that circuit, including something on the transfer switch board, that might have gone out.

Any general thoughts on where to start testing?

Click to expand...

Fleetwood uses a "BOX" called the BCC (Battery Control Center).  This BCC will be located near the batteries and labeled RV-Custom Products.

Both your chassis and coach batteries will have a large battery sized cable entering this box.  There will be three large solenoid/relays in this box.  The two larger ones are your battery disconnect relays that are controlled by the switches located by the entry door.  The smaller solenoid/relay is your aux-start/charge relay.  The large terminals on this charge relay will be connected to a large terminal on each of the disconnect relays.  There will be another large battery cable sized cable connected to the other large terminal on the coach disconnect relay.  THIS CABLE GOES TO THE GENERATOR....

Find this cable and ensure that the connections are clean and tight.  If you have a meter, measure for 12+ vdc on this cable.  You should be able to identify the other end of this cable where it enters the generator.  Clean and tighten the connections there if necessary.  This cable supplies all the power needed to start the generator from the local start switch on the generator.  Attached is a simplified diagram of the BCC.

Try starting the generator from the switch mounted on the generator.  There is no need to trouble shoot the remote start circuits and switches until you determine if you have power on that large cable (at the generator).

For information purposes... The start circuits for the generator have nothing to do with the Transfer Switch board.

Lou,

In the picture of my BCC, at the top, you can see the three relays and the one on the left, as also labeled on the cover of the BCC, is the genset. It has two lugs on it.

One lug has a larger wire on it, and the second lug is ganged back to the middle relay, and has a wire on it also.

What am I measuring to where with my voltmeter? Between the two lugs on the relay, the wired lug to ground, ???? and is that telling me I have 12 volts at that relay? I apologize for being such a basic student, but maybe others, including myself, will get a real education by following your instructions closely.

Also, I was unaware of a local switch on the generator itself, which makes some sense.

Kim

Measure from the terminals to ground.

I'm learning with you Kim.  I have my 1st multi-meter but do have a voltage meter plugged into a surge protector sitting on the diinette table! <y furnace isn't starting with any kind of click, about to take the thermostat apart and check that.

My genset is working great!

Rado Shack used to have a book on "how to use a multimeter" but now Google the quoted item and see how it goes.  There is some good stuff on the internet!!

Kim, you should measure the voltage on the large terminal to ground. 

The relay terminal that is also connected to the relay in the middle is attached to your house battery.  If you measure the voltage on each of the large terminals, the reading should be exactly the same.  This would indicate that the relay has good internal contact.

Just Lou said:

For information purposes... The start circuits for the generator have nothing to do with the Transfer Switch board.

Click to expand...

Lou,

That statement may require a little more clarification. Yesterday, I began additional testing. I had always heard a clicking when I tried the remote generator start switches. I was able to isolate the clicking to the Transfer Switch Board and can see a little red light lighting up on it when the switches are depressed.

The problem I was having with the lights dimming can be reproduced by gently pressing on that circuit board.

This is the same board that cut off power a year ago from the pedestal and the problem was resolved by tapping the clicking relays on the board. It may have finally given up the ghost.

I will now need to find a diagram to troubleshoot the problem to that board because I was told the board was $350 to replace. I would want to be sure before I made that investment.

Kim,

When you pressed on the board you slightlly stressed it and since the lights dimmed, I would suspect a poor solder joint somewhere on it.  IF you can find a qualified individual to inspect the board, they may be able to isolate the problem and fix it.  I am sure there must be others here and possibly where you are located that could do that foir you.  Who ever checks needs to understand the inspection process and use at least a 10X magnifier to do it.

Bring it with you to MT and I would be happy to take a look.  I still have most of my NASA solder station.

Jim,

You make a good case for repair. I had an LCD display in my Lexus that the factory wanted $2100 to replace. I bought the part for $125 and had a computer tech solder it in for a free lunch.

The problem will be that since it is integral to my power, I have to make a quick change out. It may be that I buy the other board, and repair the one I have for a spare. Painful, but effective.

Kim, go back and look at the photo that you posted earlier.  I can't see that it shows the relays you are discussing.

Further, I think we are having a problem with terminology or nomenclature since you seem to be mentioning the control relays and functions of the BCC (Battery Control Center) that I mentioned previously, and then intermixing the terms Transfer Switch Board into the same discussion.  These two items serve a totally different purpose.  There is usually NOT a board associated with the Transfer Switch.

What is written on the other side of that box cover (with the fuse id's written on it)?  That should tell you who made your BCC board and we can use that to find the proper wiring diagram for the relays and board.  I suspect it is Intellitec.
I think the designation "Generator" that you see written on the diagram is referring to the cable leaving the solenoid and NOT the solenoid itself.

On my Intellitec 900, there is a circuit board installed right next to the main power panel which I believe is the Energy Management Control Module and this is the board with relays.  I have a remote power management panel in the cabin.

While it may not be the transfer switch itself, it apparently has a role in the load distribution or it would not block power from switching, keep the generator from starting, or cause the lights to dim.

The red light tells me it has the ability to detect a fault, I just don't know which fault yet. I do know that everytime I attempt to remote start the generator, there is clicking at that board, and the red light flashes.

According to the Intellitec documentation, it has the ability to shed loads by circuit, and I would suspect that conversely, it could affect the power on the circuits it manages.

I am hopeful that I can get a little better troubleshooting documentation from Intellitec and I need to get the exact board number that is installed.

Since you don't seem to want to clarify what you were attempting to show in the photo, I can't do any further analysis.  Good luck with the resolution of this problem.