1987 Chieftain disconnect switch question.

[WillF]

Hey All,
    When I got this RV the Battery Disconnect switch located by the driver was replaced. Not sure if it's a SP or DP as I haven't dived into it that far yet. The switch is not a momentary DPDT switch like the original. When I switch it on it stays on. I don't think that is going to work and might end up taking the Disconnect Relay out eventually. What are your thoughts on this. I am looking for a new switch now. I think that when this switch stays locked it is draining the Chassis battery. It wouldn't be that hard for me to change it and am just thinking about doing it anyway. Thanks.

[Rickf1985]

There should be two switches, one is a momentary switch that will jump the chassis battery from the house batteries and also set the house batteries to charge from the alternator while running. This switch on my 89 is on the left of the dash. There is also a switch that turns off all power to to the coach. This switch on mine is on the right side by the radio and has a small light next to it, if the light is on then the coach power is on. Where is this switch located?


Here is the coach battery disconnect.



I don't know where my picture of the momentary switch is but I have one somewhere.
If you zoom in on this pic and look through the bottom left spokes of the steering wheel you are looking at the momentary switch.

[WillF]

Rick,
   My momentary switch that ties house to chassis is part of my dual/Chassis/Mon switch. The one on my left side is suppose to cut the house batteries and has an LED next to it. I believe itââ,¬â,,¢s supposed to be a momentary in both directions. Two owners before me put in a normal switch that doesnââ,¬â,,¢t return to neutral when released. I am concerned about leaving power to what should be momentary connect for house power going to the disconnect relay in the battery compartment. Thinking of finding a new rocker switch to install and correct it back to factory.

[WillF]

Basically the Aux Batt ON/Off is what I am referring too

[Rickf1985]

You are correct, it should only be a momentary switch in each direction. It controls a latching relay which only has power to it long enough to move the relay from one position to the other and then the power is turned off and nothing is hot until commanded to go the other way. That relay has a 5 amp fuse as part of the relay mounted on the side of it, I don't know if it would blow if left on or not. It would definitely be a draw on the battery.

[WillF]

Thanks Rick,
   That would explain why the chassis battery went dead when I had the coach battery on while trying to work on the fresh water tank drain. Oh now there is another story. LOL Will find a new switch to install. Also thinking of adding cutoffs for the negative side of the batteries for when I park the RV for a while.

[Jamo]

Where should the various switches be left so that none of the batteries go flat when everything is shut down? I keep having to jump start the engine battery almost every time I start the engine.

[Rickf1985]

If everything is working properly it does not matter what position the battery switches are in. The momentary switch will disconnect when the key is turned off and the chassis switch only has power when you are holding it. Other than leaving a light switch on there are no switches to worry about that are any different from a normal vehicle.

[Jamo]

Thanks, Rick. Sorta' takes a load off...


Jamo

[Rickf1985]

Except that you need to find out where your electrical draw is coming from that is draining the battery.

[WillF]

So threw in a momentary switch today. Only problem now is that the relay wouldnââ,¬â,,¢t latch. So new plan. Bypassed the replay by putting the positive side of the house battery to the dual relay and basically taking the disconnect relay out of play. This will allow dual mode to work. Since the disconnect is for storage going to install two waterproof cutoffs in the battery bay. One for each battery. That way when parked after the trip I can kill the whole RV. Also adding a solar panel with cutoff as well. As for the switch itââ,¬â,,¢s going to be used for LED
Lightbar upgrade on the future.

[Rickf1985]

You are talking about two different relays in your terminology, The dual switch is part of the momentary/duall switch and is a different switch from the battery shut off switch. It is a small metal relay that looks like an older Ford starting relay. The battery shutoff switch powers the latching relay which is substantially bigger, has a fuse on one side and is black plastic. I think you are trying to work one system against the other here.

[WillF]

Rick,
   When I put the momentary in I could turn the key on, switch to dual, then hold the momentary. Turn Dual back to normal, turn key off and coach lights would stay on. As soon as I released the momentary the coach lights would go off. I think they put a new relay in there for the cut-off as it looks very clean compared to the other parts in the battery bay and the relay doesn't stay in the last setting it was set to. I will have to look at the relay and get a part number for it, then I can research it. My setup is similar to the wiring diagrams used for the 90 Chieftain. Wire colors were different. You can hear the relay click when pushing the switch. And I measured power at the right pin contacts for the the momentary switch. Like I said the cut-off is for when storing the RV. So I will just move the cutoff and add another for both batteries. Will make it easier in the long run. 

[WillF]

There are two relays in the battery bay. the first one is for the Dual switch which is used to charge both batteries from the alt. The second one is the coach cut-off. There is a jumper between the two. So by  moving the coach battery to the jumper side of the dual relay, I cut the disconnect relay out of the loop. The Dual will still work. The disconnect won't Which is why I will add disconnects to the battery bay. Just a different way to do things to cut power.

[Rickf1985]

But from what I am seeing you are trying to work the disconnect from the momentary switch. They are completely different circuits. The only reason they have a physical connection is because you need the battery cable for self jump start. As far as the momentary solenoid it is not supposed to stay on once the switch is off so that you cannot drain the starting battery with the coach stuff. That disconnect relay is a latching relay so when you apply power to turn the power to the coach off it will send power to the relay which flips the contact to the other side and then the power goes off until you command it to turn the power back on. Other than the hot battery cables there will be no power showing at that relay unless you are holding the switch. Like I said, that switch on my 89 is by the radio. Once you go down the rabbit hole of rewiring those circuits you will find out that problems start compounding and there is nothing people like me or Dave can do to help without physically being there and looking at it at that point.

[WillF]

Rick,
   The problem is that the relay is NOT staying latched after releasing the momentary. It opens and cuts the coach power off. So either the relay is bad or one of the 2 other POs I know of installed the wrong relay for the cut off (Guessing the one before the person I bought it from). I will take pictures of my new circuits once I get it installed. I am a controls tech in the oil field so a simple 12 volt circuit is simple, now add in a PLC or SBC computer and addressing inputs and outputs, that gets trickier  [size=78%]. Even using 90's wiring diagrams [/size] [/size][size=78%]. There are only six wires to the switch. 2 are power and 2 are grounds. The other two in the middle send 12 volts to latch the relay in one direction or the other. Pretty simple, all I am going to do is take the relay and switch out of the circuit and add a switch in a different position to do the same thing, cut power to the coach. [/size] [/size][size=78%] [/size]

[WillF]

The other thing is the new converter I installed. The PD unit doesn't split the 12 VDC circuits like the old one did. The old converter had two 12 VDC inputs. One came on when the chassis battery was on this ran one set of lights/control panel below the oven, and the water pump. The other had to be turned on via the cutoff for the coach battery and ran the lights for the rest of the coach. My new converter doesn't do that as it filters all DC legs that come off the new fuse panel and ties all DC circuits to the converter/battery circuits. The old converter actually had an AC Ripple that was never filtered out via the converter.

[Rickf1985]

Well, It sounds like you know what you are doing and what you want to do.