power shut down 2014 Bounder 36E Shorepower AND Generator Shut Down When Engine Turned Off

[lloydwells]

Hopefully I can explain my problem correctly, as it has me kind of perplexed! LOL!

First, over the last several days I have had a couple occasions where I would go to start the engine on the coach, and there was no power (no lights, nothing). I could however, start the generator. With the generator running, I could then start the engine normally.

Yesterday however, this stopped working. I tried to start the engine and it turned over once and that was it. After that I could not even start the generator. So, I checked my starting battery and noticed the indicator "eye" was red. I took it that meant it was a dead battery. I purchased and replaced the starting battery, and the coach started easily. Problem solved, right? So, I thought.

I drove home (this was all happening on a trip of course!) and parked the coach in the shed, shut off the engine and plugged in to the 30amp shorepower. Everything came on as expected, but after 5 minutes or so all the power went off. I checked the breaker in my home, and it was not tripped.

I could not get any power to come back on in the coach (not even battery power), and the generator would not start.

Since I had the ignition problem previously, I figured I would see if I could start the coach, and it started with no problems.  

Surprisingly, about 10 seconds after the engine was running the power came back on in the coach. I was also able to start the generator again.

Then I began troubleshooting:

I unplugged the coach from shorepower, started the generator (with the coach engine running) and everything worked as expected.

Then I turned off the ignition, the generator ran for about 10-15 seconds then shut down. All power was off. Not even anything from the house batteries.

Then I did the same test with shore power connected. Same results, everything was fine as long as the engine was running (15-20 minutes at least) but as soon as I turn off the ignition, boom... no power.

Notes: I do hear a "clunk" from the battery control center, right after starting the engine (at the same time the power comes back on). I also hear the same "clunk" when everything dies after turning off the ignition.

Could the problem be in my BCC? Any tips on troubleshooting, or anyone that has had a similar issue?

Thanks in advance for any help!

[dickandlois]

lloydwells, Welcome to the FMCA Forum !

Dead Battery and engine starts with the generator running. 

Does the inverter work and what is the voltage reading on the house / coach batteries? 

What is the voltage reading on the chassis batteries with the engine running? and also the voltage reading of the coach / house batteries. Repeat the test with the generator reading and post the voltage of the batteries and post the results for both charging systems.

What are the voltages for the batteries when you are connected to shore power ?

Rich.

 

[kaypsmith]

I can relate to a similar problem with one of my coaches in the past. Please do not ignore Rich's post, but my problem turned out to be a bad ground cable connection on the generator to chassis, probably not your problem, but it sure can't hurt to make sure all ground connections are clean and tight.

[lloydwells]

Hi Rich,

Thanks for your reply! 

Not sure how to test the inverter, but the green light is on (blinking slowly) on the unit as it usually is. And the "switch" inside the coach says "AC in" and "float". Is there a way to test the inverter?(Sorry, kind of a newbie here)

Something I neglected to mention in my first post is that the issue happens even when just running off the house batteries (no gen or shore power) Everything stays on indefinitely as long as the engine is running, but after the engine is shut off everything goes.

In some additional troubleshooting this afternoon, it seemed like the more things I turn on in the coach, the quicker the power shuts off. I tried once with only the LED porch light on, and it didn't shut off for 15 minutes (this was on 30A). I also tried once with several lights and one A/C unit on, and it only stayed 3-4 minutes (also on 30a).

As for readings:

Chassis battery 12.46 (engine off), 14.18 (engine on), 14.15 (gen on), 14.15 (SP on)

House batteries 6.40 each - 12.77 together (engine off & engine on), 6.60 each - 13.25 both (gen on), 6.60 each - 13.23 both (SP on)

Thanks for the help!

Lloyd

 

[lloydwells]

Will definitely check all grounds tomorrow. Thanks kaypsmith!

[wildebill308]

Richard and Kay have some good ideas. 

We appear to have 2 different problems. 1 before you changed the start battery and 2 after you changed the battery. The first one should be fixed. Have you checked the voltage of the auxiliary batteries?  In the area of your BCC you should have a big solenoid that tyes the batteries together when you hold the switch down. Check the voltage at the post where the big cables connect. One side should be the same voltage as the start battery and the outher the auxiliary battery.  Have you tried to start the generator by holding that switch down? Have you removed and cleaned all the auxiliary battery cables including ground?

What it sounds like is you are not geting 12 power from the battery's to the system via the BCC. When the engine is running it provides the necessary 12V power to operate all the controls. That is why when you shut off the main engine the shore power quit.  Without 12V power the transfer switch won't stay engaged the fuel pump to the generator won't work. The furnace won't run. anything that needs 12V power will shut down. 

Let us know what you find out.

Bill

 

[lloydwells]

18 minutes ago, WILDEBILL308 said:

In the area of your BCC you should have a big solenoid that tyes the batteries together when you hold the switch down. Check the voltage at the post where the big cables connect. One side should be the same voltage as the start battery and the outher the auxiliary battery.  Have you tried to start the generator by holding that switch down? Have you removed and cleaned all the auxiliary battery cables including ground?

 

I'm a little confused here... I think the solenoid you mentioned is actually inside my BCC unit (rv custom products gas f73-1020). Should there also be an external solenoid? The one inside the BCC unit is the one that makes an audible "clunk", both when the power comes back on after starting the engine, AND when it goes off after the engine is turned off. I've listened to it with the cover off the BCC, and that's definitely where the sound is coming from.

Also, what is the "switch" you mention above? I don't have an auxiliary start switch (that I know of) if that is what you mean.

Here are my readings:

32 minutes ago, lloydwells said:

Chassis battery 12.46 (engine off), 14.18 (engine on), 14.15 (gen on), 14.15 (SP on)

House batteries 6.40 each - 12.77 together (engine off & engine on), 6.60 each - 13.25 both (gen on), 6.60 each - 13.23 both (SP on)

I definitely think you are on to something with the lack of 12v power thing. I just have to track down the culprit!

Thanks again for all of the help (and thanks in advance for the continued help!)

[lloydwells]

Additional info: Yes, I DO have an auxiliary start switch (we got little or no "orientation" when we bought this coach, and it's been a trial by fire for the last couple years.  But now that the starting battery is new, I don't know if trying to start the gen with that, would tell us anything, would it?

And my inverter seems to work as advertised. It powers the TV's and a couple specific outlets. Of course once I turn the engine off it all dies, so I don't have much time to check everything. lol

[dickandlois]

Lloyd, The readings on the batteries are with in the range one would expect - that being the case and the inverter running normally takes the charging systems out of the mix.

Frrom your last post - it sounds like all the 120 volt systems are working and the inverter output is working. That place the problem in the wiring for the 12 volt system.

Of course once I turn the engine off it all dies --- This is the key to the problem.  The Key is to find out why the 12 volt system drops out shortly after the engine or generator are turned off. Sounds like from your description that there is a relay dropping out 

A decaying 12 volts - holds the circuit on until a voltage drops some and at that point in the circuit drops below the ability to keep the relay closed. 

12 volt disconnect circuit / also known as the salesman switch. accomplishes the same results - turns off all 12 volts to the coach, BUT not to the chassis 12 volts.  Make one test for me ! Do the electric steps work - when the problem of no 12 volts happens ?

Kind Of thinking, Kay might be on to something - regarding the coach battery ground connections. Good ground connections issue is at the top of the list for many intermittent problems ! 

Rich. 

[elkhartjim]

I had an issues several years ago that the genset would die. I would restart and it would run for several minutes and die or it may run for a much longer time and then die. It was a loose ground connection on the house batteries. I tightened it and solved the problem.

Seems to me, 75% of our electrical problems are poor ground connections.

 

[hermanmullins]

Jim,

You are correct about the Ground connections on RVs. There are so many and there doesn't seem to be one central common ground point. But as you said start with the ground. I had an issue once with my Inverter. Even went so far as to remove it and have it bench tested. It was fine. When removing it I found that the common ground between the shore power and the Generator was a bit loose. Upon reinstalling the unit and being sure all connections were tight I haven't had a problem since.

Ah Ground, so hard when you hit it , but so necessary for electricity.  

Herman

[lloydwells]

2 hours ago, DickandLois said:

The Key is to find out why the 12 volt system drops out shortly after the engine or generator are turned off. Sounds like from your description that there is a relay dropping out 

Just to clarify, the generator running does not solve the issue. Only the coach engine running keeps everything running. If I shut the engine off, and the genset is running, it will die shortly afterwards as well. So, both the genset and shore power react the same way. (As do the house batteries when the coach is running with no shore power OR generator running)

2 hours ago, DickandLois said:

Do the electric steps work - when the problem of no 12 volts happens ?

Yes, just tested this and the steps work even when nothing else will.

Like I mentioned before, once the power goes, the only way I can get it to come back on is to start the engine.

I did do one additional test just now. Since I couple folks have mentioned the "auxiliary start switch" in regard to starting the generator, I tried that this morning. Once the power goes off, I cannot start the generator (in fact nothing on that panel, fans, lights etc, work). BUT this morning, I held the "auxiliary start switch" and was able to start the generator WITHOUT first starting the coach engine. Does that mean anything?

Also, there is a 12v disconnect switch (near the inverter), I think what you were referring to as the "salesman switch". This switch is in the "on" position

[wildebill308]

I think it is a problem getting power from your auxiliary battery's. The steps are powered from the start battery. When you hold down the "auxiliary start switch" you are routing power from the start battery's to the BCC and to the rest of your coach 12V system. Check the voltage on the main cable going into your BCC. 

Bill

[kaypsmith]

All lights in the overhead are 12 volt supplied from the house batteries, with this said, things are narrowing down to a house battery issue. The ground system to those batteries would my primary concern. The clunking sound that you are hearing is that relay dropping out and coming back on when the engine is starting. The battery voltage seems good based on what you have reported. As said earlier if voltage drops below a reasonable voltage level that relay should not be dropping. I would at this point disconnect each battery in the house battery compartment, taking pictures as you go, and marking each wire to make sure that they are reinstalled correctly. Check the voltage level on each one separately looking for any noticeable difference in voltage. One bad cell can cause strange things to happen. Another thing that I have seen happen is that the house battery bank should have a ground from the batteries to the metal shield if there is one around the batteries, and also to the chassis frame, one simple way to test if this is a problem is to use a jumper cable from the negative battery post directly to the frame rail of your coach, of course I'm speaking of the house batteries. My theory right now is that the house batteries are achieving their through the alternator while the coach is running or being backfed when the auxiliary start switch has been activated.

[lloydwells]

Think I may have found it. Tested 12v power at BCC... got 12.5 or so from chassis battery side, and only 1.9 from house batteries. So I went back to house batteries. There are two 200A fuses inside the battery compartment. When tested, one had 12+ volts on both sides of the fuse, the other had 12+ on the battery side, but only 1.9 on the "out" side. I removed the fuse and tested resistance to 1 ohm... bad fuse.  So I am off to get a fuse, and I will update when it's installed.

Thanks again!

 

[kaypsmith]

Sounds like great news, hope it fixes it.

[wolfe10]

Not sure I understand.  A fuse with only 1 ohm resistance is good.  One with infinite resistance aka open circuit would be bad.

[wildebill308]

I agree Brett, I think there is a bad contact in the primary power cable. I still recommend taking the cabled loose and clean and inspect them. Especially the main one from the auxiliary battery's to the BCC.

Bill

[lloydwells]

I guess I misstated... not 1 ohm, but the meter never moved from the big "1" that it starts on. Also, getting 12.5 on the battery side, and 1.9 on the out side, pretty much told me the fuse was bad.  Just got a new one and going to replace it now. Will update soon!

[wolfe10]

Yes, if the ohm meter did not change when touching the two ends of the fuse, it is BAD.

Said another way, resistance across a good fuse is quite a lot lower than across "air"/before you touch the probes to anything.

[hermanmullins]

My theory is if it measures 12 volts on both sides of the fuse = GOOD fuse. If is measures 12 volts on one side and "Zero" on the other = BAD fuse.

But what the heck everyone will tell you I am simple, or is that a simpleton".

Herman

[lloydwells]

UPDATE: New fuse installed. Voltage at 12+ on both sides of new fuse. Voltage at 12+ at the BCC on both the chassis and house battery inputs. All power is back on in coach. I ran on the generator for about 15 minutes without losing power, and now I'm on 30A shore power with no problems so far. :))) (All without even having to start the engine!)

So, thanks to everyone's input we were able to track this down, and it ended up being a fairly simple solution and a cheap part (not including my labor fees of course! LOL)

I'm attaching some photos here of the old and new fuses, the location on the fuse(s) in the battery compartment, and the block with the new fuse installed. In hopes that if someone else has this problem, this info will help them out. I need all the good karma I can get!

Thanks again to everyone who posted. ALL of your information was helpful, and contributed to helping me fix this problem.

Safe travels!!!

Lloyd

[kaypsmith]

Herman, we'll just start saying SIMPLE HERMAN instead of simple simon. I also saw the 1 ohm, but not knowing his meter, and 1.9 volts just is not right, or southern talk "just ain't right", and I'm so red neck, don't have to wear a shirt.

[dickandlois]

This fuse does not fail very often! The last one that I found on a coach - was damaged when a tow truck drive thought those big terminals would make a good spot to jump start a coach. Coach's are not just trucks with an oversized cab.

The owner really  had no clue regarding where to connect the jumper cables. 

Rich. 

[wildebill308]

Yes if you don't have 12V power from the auxiliary batteries nothing works. 

Bill