Battery disconnect switch

[John How]

Today while working on the installation of my inverter, I hit the battery disconnect switch and hear the click of a solinoid somewhere up front of the side door where the switch is located. However, I flip the switch above it to turn on the interior light in the living area and on it comes as do all the 12 volt lights. Now the coach is UNPlugged from shore power while this is going on. I am unfamiliar with how this switch should work but I do believe I should not have 12 volt lights when it is in the disconnect position. Anybody got an idea?
Thanks!

[Wi1dBill]

Just a thought, do you have another battery for the engine? Could be that light is wired from that.

[Old Bounder]

Originally Posted by John How

Today while working on the installation of my inverter, I hit the battery disconnect switch and hear the click of a solinoid somewhere up front of the side door where the switch is located. However, I flip the switch above it to turn on the interior light in the living area and on it comes as do all the 12 volt lights. Now the coach is UNPlugged from shore power while this is going on. I am unfamiliar with how this switch should work but I do believe I should not have 12 volt lights when it is in the disconnect position. Anybody got an idea?
Thanks!

Your thinking is correct if the Daybreak uses the same Battery Control Center that the Intruder does. My Bounder disconnect switches are labeled rather confusingly. The ON position (pressing the top of the switch) actually means the batteries are ON (or connected). The OFF condition means the batteries are disconnected.

[John How]

The switch positions are labeled connect and disconnect, but either way the lights will switch on. The power is coming from the house batteries because when I physically remove the battery wires they go out. Before I unhooked the batteries though, I could hear a click when I make or break the switch.

[Ray,IN]

Defective solenoid?

[YC1]

Originally Posted by Ray,IN

Defective solenoid?

OR, someone bypassed the contacts. Leaving the solenoid in place.

[John How]

Ok, I did some more trouble shooting today on the battery disconnect. As I said before, I can hear the solenoid click when I make the switch either way ( connect or disconnect) but the battery does not disconnect, it is always connected and the lights stay on. I enlisted some help today while I checked voltages. The top solenoid in the BCC is the disconnect. As I said it's always connected, 12 volts on both side of the large battery terminals. The switch is a three position rocker, centered is neutral, up is labeled "battery disconnect" and down is labeled "battery connect". When the switch is held up, I get 12 volts the the grey control wire at the solenoi, and when the switch is held down, I get 12 volts at the purple control wire at the solenoid. I can hear the solenoid click when the switch is thrown either way but the battery is never disconnected. Sounds to me like a bad solenoid, do you agree? There is a black plastic affair on the top of this solenoid with a pair of 5amp fuses in it. Possibly one of them is a spare as I don't any wire running to it, they are both good though. Thanks for your input.

[John How]

Another thing I just discovered, and it seems wrong to me, is that the bottom relay which I think is the battery boost for starting, is always energized and has 12 volts in and out even with the ignition off. I removed the ground lug at the car battery and then I see no voltage to one side of that solenoid and 12 volts from the house battery on the other side. It just doesn't seem that the two batteries should be connected all the time.

I did try disconnecting the house batteries with the switch while I had the car battery ground lug off and they still did not disconnect.

[Hooligan]

Sounds like the battery boost (aux Start) relay is stuck on, connecting the two batteries all the time. If the disconnect relay clicks it is probably operating but the Aux start relay is bypassing that relay. Could be the aux start relay or it's switch.

[YC1]

A couple of pictures would help tremendously.

As for the Boost relay being energized all the time I think you are getting fooled.
First, feel it to see if it is warm or hot. Then measure the voltage on the small terminals that control it. Since you removed the ground from one of the battery banks and the voltage went away on one side of the solenoid it appears it is NOT energized all the time.

IF you see voltage on one of the little terminals and 0 volts on the other small terminal then it should be energized and you would see voltage on both sides of the large terminals.

[John How]

Originally Posted by YC1

A couple of pictures would help tremendously.

As for the Boost relay being energized all the time I think you are getting fooled.
First, feel it to see if it is warm or hot. Then measure the voltage on the small terminals that control it. Since you removed the ground from one of the battery banks and the voltage went away on one side of the solenoid it appears it is NOT energized all the time.

IF you see voltage on one of the little terminals and 0 volts on the other small terminal then it should be energized and you would see voltage on both sides of the large terminals.

Ok, I think I see what you mean and I am getting fooled. Just because there is 12v on either side does not mean it is energized since each side is connected to a 12v battery. When I disconnect at the car battery, one side of this relay(or solenoid) goes to zero so it s not energized all the time.

Here is a pic of the BCC

[YC1]

OK. Part two. The relay on top appears to be your "salesman solenoid". It also appears to be a "latching" type solenoid. Meaning it needs voltage to energize it but not to stay energized.

The black plastic split loom is blocking the picture but it almost seems to have a light wire jumper from the left to the right large posts.

To check to see if the solenoid is cycling on and off you need to remove all of the wires from one of the large posts. Remove the one that feeds the fuse panel or circuits and not the one from the battery feed. Use a nut and bolt to keep them together and wrap them with a rag to prevent metal contact or you will have a big problem.

Without a schematic I cannot be 100% certain this test will work. Now cycle your on/off switch while listening for the clunk of the relay. Then measure the voltage on the empty post to see if voltage is cycling on and off. If it is the solenoid is ok. If not AND you did hear it clunk, use the handle of a screwdriver and wake it up with a good whack.

Of course, the other thing to note is removing the output side of the solenoid should immediately turn the interior lights off if not bypassed somehow.

[John How]

Thanks very much for your experienced help YC1, I will follow your TS directions later today and see what gives. I also found this PDF which seems to give a good explanation of the workings. It should be but isn't (well until now) included in my Damon manual.
http://windsurf.mediaforte.com/roadt...5322019100.pdf

[YC1]

Excellent schematic. I saved that one. So simple.