Chassis battery disconnect revisited.

[Rodallg]

Time to look into the chassis battery disconnect again. I have been putting it off since it requires me to demount a terminal/fuse board to get to the relay behind it. My question is now, what is disconnected with that switch? Is it just used for the starting the engine?

[rvten]

Let us know what you find out.

[Rodallg]

OnaQuest wrote:

Rodallg wrote:
The chassis light on the disconnect panel. I assume that if I tried to disconnect the chassis then tried to start the engine it would not have power to the ignition switch. It will start after trying to disconnect.
2000 Mountain High Pinnacle on a F53.

This is normal for later revisions of the BCC circuit board. Earlier Revs. would not allow starting (would not override the disconnect) if the disconnect had been activated.

Does the light remain ON when disconnect is activated, even when the ignition if OFF, or just if the ignition is on? It actually should go off if the ignition is OFF when the switch is activated.

Is your BCC (the box containing the circuits and solenoids) made by Intellitec or RV Custom Products? I have diagrams and trouble shooting procedures for both if you will PM me.

PM sent.

[OnaQuest]

Rodallg wrote:
The chassis light on the disconnect panel. I assume that if I tried to disconnect the chassis then tried to start the engine it would not have power to the ignition switch. It will start after trying to disconnect.
2000 Mountain High Pinnacle on a F53.

This is normal for later revisions of the BCC circuit board. Earlier Revs. would not allow starting (would not override the disconnect) if the disconnect had been activated.

Does the light remain ON when disconnect is activated, even when the ignition if OFF, or just if the ignition is on? It actually should go off if the ignition is OFF when the switch is activated.

Is your BCC (the box containing the circuits and solenoids) made by Intellitec or RV Custom Products? I have diagrams and trouble shooting procedures for both if you will PM me.

[Rodallg]

kdk wrote:
It sounds like the chassis disconnect relay may be DE-energizing when you actuate the switch but the relay contacts may have arced and welded together. First put your hand on the relay and have someone else flip the switch to make sure you are working with the correct relay, when the switch is activated you should feel a pretty good thump. After verifying you have the correct relay and the disconnect switch is activated take a volt meter and read the voltage on the large terminals both sides. You should read battery voltage on one side (12.4-12.6 volts dc) and zero volts on the other side. If you have voltage on both sides then read the voltage to the small terminals. Both of the small terminals should be zero volts ( some relays have only one small terminal others have two. On the relays with 2 small terminals one wire comes from the switch and the other to ground, relays with only 1 small wire are internally grounded and the single small wire comes from the disconnect switch). Using your volt meter determine which wire comes from the switch and disconnect it, if you then still have voltage on both sides of the large terminals then the relay contacts have welded together and needs replacing.
I know this is long and may be hard to understand so feel free to PM me and I would be willing to talk to you on the phone. KDK

This is exactly the troubleshooting I needed. Now I just need to get to the relay, its behind an circuit/fuze board.
Thank you.

[kdk]

It sounds like the chassis disconnect relay may be DE-energizing when you actuate the switch but the relay contacts may have arced and welded together. First put your hand on the relay and have someone else flip the switch to make sure you are working with the correct relay, when the switch is activated you should feel a pretty good thump. After verifying you have the correct relay and the disconnect switch is activated take a volt meter and read the voltage on the large terminals both sides. You should read battery voltage on one side (12.4-12.6 volts dc) and zero volts on the other side. If you have voltage on both sides then read the voltage to the small terminals. Both of the small terminals should be zero volts ( some relays have only one small terminal others have two. On the relays with 2 small terminals one wire comes from the switch and the other to ground, relays with only 1 small wire are internally grounded and the single small wire comes from the disconnect switch). Using your volt meter determine which wire comes from the switch and disconnect it, if you then still have voltage on both sides of the large terminals then the relay contacts have welded together and needs replacing.
I know this is long and may be hard to understand so feel free to PM me and I would be willing to talk to you on the phone. KDK

[Rodallg]

rvten wrote:
OK but what light stays on?
See if that light is connected directly to batt. By passing the disconnect switch.

How about year and make and model if RV.
Maybe someone else has same or better idea what to look for.

The chassis light on the disconnect panel. I assume that if I tried to disconnect the chassis then tried to start the engine it would not have power to the ignition switch. It will start after trying to disconnect.
2000 Mountain High Pinnacle on a F53.

[rvten]

OK but what light stays on?
See if that light is connected directly to batt. By passing the disconnect switch.

How about year and make and model if RV.
Maybe someone else has same or better idea what to look for.

[Rodallg]

rvten wrote:
What light stays on?
When you turn off the coach disconnect. Switch and are plugged into shore power. You will get 12 volt from the converter. But it will stop charging your coach batts.

Do you have 2 disconnect. Switches? One for coach and one for chassis?

2 disconnects, coach and chassis, the light for chassis stays on after pushing the switch to disconnect, relay clicks and light stays on. Coach disconnect works as it should.

[rvten]

What light stays on?
When you turn off the coach disconnect. Switch and are plugged into shore power. You will get 12 volt from the converter. But it will stop charging your coach batts.

Do you have 2 disconnect. Switches? One for coach and one for chassis?

[Rodallg]

rvten wrote:
Battery disconnect switch is normally just the coach batts.
Some of the older MH's I had. Had a disconnect. For the coach and engine batt.
(Chassis batt )

So what are you looking to do? Add a disconnect for the chassis?
A little fuzzy on your post.

Should of added that my problem is that when I disconnect the chassis I hear the relay but the light stays on and it doesn't disconnect.

[rvten]

Battery disconnect switch is normally just the coach batts.
Some of the older MH's I had. Had a disconnect. For the coach and engine batt.
(Chassis batt )

So what are you looking to do? Add a disconnect for the chassis?
A little fuzzy on your post.