Now I Did It! No 12vt Power!

[Stan&Jacquie]

I had my 07Knight running on the genset and was pulling in the full length slide when all 12vt power failed. The genset failed and now there is no power to interior lights, the power seats and more.

How do I go about diagnosing this? What should I be looking for?

[Coaster1]

Transfer switch stuck, breakers on genset. breakers in coach, just a guess.

[palehorse89]

Start in the battery compartment with the voltage of the battery's and the connections, are the clean? When did you clean them last? Sounds like you lost your battery (12vdc) connection to the Coach, genset and so forth.

[mahon1993]

You didn't by chance bump the "salesman's" switch did you. That switch usually near the entrance door that kills all the 12 volts to the coach.

[RWeigant]

Yes, look at the switch by the door and also on ours there is two battery disconnects located next to each battery.

[Mike Canter]

I seriously doubt that the salesman switch will cause the generator to quit also. I believe that Palehorse is correct in that you lost 12 volts from the batteries. The question is if it the chassis or the house batteries. Normally the generator uses the chassis batteries and the lights use the house batteries but the chances of losing both battery sets at the same time is possible but improbable. Bringing in the slide out uses a lot of amps and if the battery cable connections or dirty or loose then that could be the problem. If the generator circuit breakers popped then it would not shut down the generator. FIRST THING is you need to go and look at the generator start switch that is on the generator and see if a red light in the switch is flashing. If it is then press the bottom half of the rocker start switch so it will start flashing the two digit failure code and tell us what it is. After that then I would clean all the battery cables. First use a baking soda solution to remove corrosion from the terminals and dip each end of the cables in the baking soda solution and then wire brush the battery posts and cable ends. After the batteries have been cleaned off then it is a good time to check the battery water levels.

[Stan&Jacquie]

Originally Posted by Mike Canter

I seriously doubt that the salesman switch will cause the generator to quit also. I believe that Palehorse is correct in that you lost 12 volts from the batteries. The question is if it the chassis or the house batteries. Normally the generator uses the chassis batteries and the lights use the house batteries but the chances of losing both battery sets at the same time is possible but improbable. Bringing in the slide out uses a lot of amps and if the battery cable connections or dirty or loose then that could be the problem. If the generator circuit breakers popped then it would not shut down the generator. FIRST THING is you need to go and look at the generator start switch that is on the generator and see if a red light in the switch is flashing. If it is then press the bottom half of the rocker start switch so it will start flashing the two digit failure code and tell us what it is. After that then I would clean all the battery cables. First use a baking soda solution to remove corrosion from the terminals and dip each end of the cables in the baking soda solution and then wire brush the battery posts and cable ends. After the batteries have been cleaned off then it is a good time to check the battery water levels.

I

Ok...great advice here guys. Yes, I tried/checked the salesman switch first....no luck. No light on the genset switch and the breaker was not tripped. Will check battery voltage tomorrow but I doubt that is the culprit. Genset was running over an hour in abs orb mode before problem occurred. Coach started right up after the failure. Had coach out two weeks ago for two days without incident.

I'm still befuddled! Keep those great ideas coming!!!

Stan

[Mike Canter]

That's more great info so it is not the chassis batteries. Does the generator start ok? if not have you tried starting the generator via start button on the generator?

[Stan&Jacquie]

Originally Posted by Mike Canter

That's more great info so it is not the chassis batteries. Does the generator start ok? if not have you tried starting the generator via start button on the generator?

Gen won't start due to lack of 12vt.. Tried all 3 start locations. Did check and tried to reset the breaker on the gen.

[86 Cavalcade]

Stant, On some of these coaches Monaco used a wiring harness that had plug together wiring harness that ran from the front to the back. If you search this forum for postings by Drifter or RobinM you will see what problems they had with these high amperage 12 volt connectors. Drifter had a posting on 8-05-2012 at 02:02 AM. If you have 12 volts at your house battery bank and you don't have 12 volts at your front run bay you may want to look at these connectors. Good luck, George 2001 Diplomat

[Playtime III]

Had this happen to me only with the levelers causing the outages. I tripped a main breaker in the engine bay. On my Scepter 42DSQ there is a black box (18x18) in the upper right corner of the engine bay. the cover is held in place by three wing nuts. Under the cover is a large breaker that had tripped. Unlike 110v breakers this one swings (like hands on a clock). Once reset, good to go.

[Dr4Film]

Since your generator is using the HOUSE battery bank for starting, I would start there and make sure all connections are clean and secured tightly.

Next, look closely at the HOUSE Battery Cut-Off Switch making sure that voltage is going from the battery bank to the switch and then through it to the other side.

Next, check the battery isolator relay. Speaking of this relay, what happens when you hold the Battery Boost Switch which connects the two battery banks together and then try starting the generator?

Then you probably have a couple of 12 VDC relays that need to be checked making sure you have voltage going from one side to the other.

Basically, you need to start at the HOUSE batteries checking your 12 VDC voltage flow through ALL devices until you find where it stops. Once you do that, you will find the culprit.

Of course you need a good VOM meter to use while conducting your readings.

Dr4Film ----- Richard

[Stan&Jacquie]

Originally Posted by 86 Cavalcade

Stant, On some of these coaches Monaco used a wiring harness that had plug together wiring harness that ran from the front to the back. If you search this forum for postings by Drifter or RobinM you will see what problems they had with these high amperage 12 volt connectors. Drifter had a posting on 8-05-2012 at 02:02 AM. If you have 12 volts at your house battery bank and you don't have 12 volts at your front run bay you may want to look at these connectors. Good luck, George 2001 Diplomat

Case solved! With much assistance from all ofbyour considerate and informed posts I was able tmo locate the problem. It appears that the battery disconnect switch in the battery bay led directly to a highbamperage circuit breaker. As suggested in this forum, I got out my meter andstarteid following the 12v path. Batteries seemed good and voltage was good on the battery side of the breaker. The othervside of the breaker showed a big loss of volts. The connection was both somewhat loose and very corroded.

I cleaned the connection and then proceeded to take this opportunity to clean and properly torque everything that was bolted together.

Thanks to all!!! coach is up and running!!!

[CLIFFTALL]

Thanks for updating us. Glad it's working.