Community Forums

CrownRoyale · 12-21-2020, 09:42 AM

So I took my 95 Crown Royal to a repair shop to get the radiator replaced they had the coach for approximately a month. The day before I picked it up they informed me that the batteries were completely dead which I thought was odd because the they are less than a year old. I figured that they either didn't want to tell me they left something on or they weren't aware they left something on and drained the batteries. Either way they put the coach on a charger for a full day before I picked it up. It started right up and had no issues with the 60 mi drive home. When I arrived at home I parked the coach in my shop and plugged it into 110 power just so I could run the Aqua Hot system set on low. The next day I was working in the shop and I heard a beeping sound coming from inside the coach. When I open the door the whole inside was filled with smoke from the electrical fire!!! I immediately unplugged the 110 extension cord that I had plugged in via the adapter to the 50 amp plug. I also unhooked all of the batteries. During my inspection I found that the battery parallel solenoid had somehow burn up. Thinking back this is probably what drained the batteries at the repair shop. So I'm just digging into this and looking for parts and or maybe reasons why this happened. I just put all brand new tires brand new radiator brand new brakes etc on the coach and I don't want to lose it especially when it's parked inside my shop!
So right now I'm looking for a battery parallel solenoid.
I see no markings as for part numbers anywhere on it.
Obviously I'm going to have to replace some cables and maybe the battery isolator block itself as well.

RamiDav · 12-21-2020, 09:56 AM

Many coaches have a solenoid / relay called big-boy. Yours may or may not have that.

Some people are using a solenoid from the boating world with easy excellent results.
Read this thread about it.

https://www.irv2.com/forums/f115/rep...cr-468617.html

Outbound · 12-21-2020, 10:56 AM

Your very lucky coach did not burn down, looking at photo damage appears positive went to ground.

CrownRoyale · 12-21-2020, 11:21 AM

Yeah it definitely got hot... Battery cable on solenoid was orange hot (you can see it just below the bottom left of isolator block)and the cable you see burnt in pic (isolator block) is from the heat the other cable was putting off.

Timaz · 12-21-2020, 11:58 AM

Luckily you went out to your coach. Please update when you confirm what the failure point was.

Tim

JBDISCOVERY · 12-21-2020, 12:03 PM

West Marine sells those battery isolators for marine use.
Should work in an RV.
JimB

CountryB · 12-21-2020, 12:14 PM

Quote:

Originally Posted by CrownRoyale

During my inspection I found that the battery parallel solenoid had somehow burn up.

Thinking back this is probably what drained the batteries at the repair shop. So I'm just digging into this and looking for parts and or maybe reasons why this happened. I just put all brand new tires brand new radiator brand new brakes etc on the coach and I don't want to lose it especially when it's parked inside my shop.

So right now I'm looking for a battery parallel solenoid.
.

I believe what you are calling a "parallel solenoid" is actually the "start boost solenoid". That is the solenoid that connects the Chassis and House batteries together when you press the switch on the dash, to aid in starting (cranking) the engine.

However even if that switch was stuck On, so the two battery groups were connected, it would not start a fire. The solenoid could overheat from being in the closed position (since it is not a "continuous duty" solenoid) but I don't know if that could actually start a fire. There may be a deeper/root cause like a large battery cable that shorted to ground. Etc.

twinboat · 12-21-2020, 12:46 PM

Quote:

Originally Posted by CountryB

I believe what you are calling a "parallel solenoid" is actually the "start boost solenoid". That is the solenoid that connects the Chassis and House batteries together when you press the switch on the dash, to aid in starting (cranking) the engine.

However even if that switch was stuck On, so the two battery groups were connected, it would not start a fire. The solenoid could overheat from being in the closed position (since it is not a "continuous duty" solenoid) but I don't know if that could actually start a fire. There may be a deeper/root cause like a large battery cable that shorted to ground. Etc.

The parallel solenoid is the same as the boost solenoid. It parallels the house and chassis batteries to boost start it.

153stars · 12-21-2020, 01:07 PM

I have same coach. I'm trying to wrap my mind of why it would happen exactly. The solenoid is only to combine batteries at boost switch. The diode isolator is to combine while driving. There's also several fuses the round black plastic ones I'm sure they can't protect every possible short. I watched vid of Bluesea brand ACR amp draw tested between large batteries one set low charge one high ,the amps drop off faster than one might think without cranking a motor.
Possibly cause arching from positive to positive then to ground of the can IDK but why was it engaged. If you consider the magnetic latching Buesea ACR it can replace big boy and the diode isolator . It will enable bi- directional charging and get house batteries fully charged .The diode isolator drops half a volt doesn't really affect alternator charging chassis due to battery sence wire. There's a few posts of Bluesea ACR if you search with pics an diagrams.

CrownRoyale · 12-21-2020, 02:54 PM

The battery parallel relay. Number six in this picture

Biljol · 12-21-2020, 06:57 PM

Do you ever use the boost function. I don’t so have removed it. I am also removing the isolator and replacing it with a dc/dc charger. Also removing the maintainer although I believe mine was bad since the light was on with the house battery’s at 10 volts. Also using a dc/dc charger for the other direction.

I know there’s the convince of the boost relay but there are other options that are not connected all the time and complicating the system.

I am in the process of reworking my coach into the kiss system (keep it simple stupid). I think sometimes the stuff they did in the 90-2000 are lipstick on a pig. “Look you can jumpstart your rv without leaving your seat” instead of make sure you you don’t run your starter battery’s down and keep them in good shape.

I feel the same on the “salesman switch” it will “turn off all your 12 v so you don’t run the battery’s down” —— oops yes there are X items that you can not turn off.

Sorry about the rant I am working my 12v system now and some thing they did just don’t make any sense.

CrownRoyale · 12-22-2020, 05:38 AM

Yes it seems over complicated.

Biljol · 12-22-2020, 05:47 AM

Yep like let’s run this line from the house battery’s all the way to the front of the coach to the inverter then 120v all they way back to the breaker panel in the bedroom then all the way back to the front ac unit.

I really think if someone sat down and found the most efficient way to run all the wiring in a coach they would be at lest a 1000lbs lighter.

I know it’s run that way for the labor costs right,.

CountryB · 12-22-2020, 06:19 AM

Quote:

Originally Posted by twinboat

The parallel solenoid is the same as the boost solenoid. It parallels the house and chassis batteries to boost start it.

Thanks Twinboat. I was only mentioning it in case the OP is trying to buy one - it may be easier to locate the part using the term "start boost solenoid".

I see that the post with the picture does call it a "parallel solenoid". I was surprised to see that term used (I supposed it is technically it is more correct) but not as commonly used.