Need info on operation of battery disconnect.

[CapnDirk]

Was just diagnosing the dead light on the dash that would show the coach batteries were cut in and discovered that the battery disconnect was on all the time regardless of what you did with the switch.  You could hear a thunk when switch was used to turn on or off but no change.  I replaced the disconnect unit and label on the face matched what I found on old one for wiring placement.  However, there is no change and the disconnect is straight through on the battery cables. 


I have the wiring diagram which shows one of the fuses on top is for the indicator light (on the outgoing side)  and the other is for 12V supply to the rocker switch at the dash.  The two terminals on the side go to the switch as well.  I'm assuming it would be those that kick it one way or the other.   I have the switch hanging out of the dash, and the diagram for the switch shows this color to #1, this color to #5, yada.  However, there are no numbers on the switch case, so I have no way to determine if someone got it hooked up wrong.


Is the disconnect itself a NO or NC device?  Or does it just kick one way or the other when a pulse (dash switch is momentary) is sent to one of those two side terminals?


Is there life after electrical?  Getting worn down by it.   


Thank you all for your patience. 

[DaveVA78Chieftain]

Battery disconnect relay uses a latching mechanism so that a constant control voltage does not have to be applied to it to latch in either position (ON or OFF).  A pulse (plus/minus) is sent to it to latch in the ON direction. A pulse with opposite polarity (minus/plus) is sent to it to latch OFF.  Simply put, the control wires are reversed to switch directions.

[CapnDirk]

Thanks again Dave.  That confirms what I thought and why there are negative lines going to the switch.


I have not found any info on the mechanics of the switch itself and doubt I will.  Without knowing which pin is which on the back of the switch I have no way of knowing if the switch is wired correctly.


I suppose my first action would be to pull the side wires off the disconnect unit and use jumper wires  to send + and - to them from the battery and see if it disconnects and re-connects with polarity reversal.


Looking at the schematic of the switch itself, it shows six terminals, the two in the middle are the outgoing lines to the disconnect.  That is the case on my switch, and the diagram shows a + line on the left and - line on the right below them.  Above them it shows a - on the right and + line on the left.  Mechanically this makes sense as 4 contacts (two and two to channel + and -) would be used, then the reverse polarity would happen when the switch was thrown the other way.


My switch, the two control lines are in the middle, two positive above, and two negative below.  I've been hesitant to experiment with the switch itself since it has both + and - on it and getting it wrong would of course cause a meltdown when the switch was thrown.


I dearly hope that the new disconnect has not been fried sending + to both lines of the device as that is what the above layout at the switch suggests.

[DaveVA78Chieftain]

http://www.classicwinnebagos.com/forum/index.php/topic,5977.msg22985.html#msg22985

[CapnDirk]

It seems I keep saying "thanks Dave" 


OK, with some studying and Dave's link I figured the switch out.  PO had left the two wires in the middle of the switch to the disconnect relay alone, and put both grounds on one side, and both positive on the other.  Assuming the contacts inside were parallel I left the middle wires alone, and arranged  the + and - in an X pattern.  My volt meter (does show polarity)  showed 13.4 volts at the middle wires and reversing.  I still have battery positive on both sides of the disconnect switch no matter what the disconnect switch does.


With my buddy running the switch I check the lines at the disconnect and they to are reversing,    .  OK, lets pull the outgoing battery lines and see what we get.  Switch on and switch off are working correctly!  ?  Well, if it wasn't coming from the disconnect switch being latched closed, lets check the outgoing cable.  It's hot!  Coming back from where?  Battery boost solenoid! Switch good, solenoid not so good.

AAAAAAAARRRRRRRGGGHHHH!!!!!

[DaveVA78Chieftain]

It seems I keep saying "thanks Dave" 

Let's just say your not the first person that's come to this rodeo.
When you do post parts you have installed/repaired, please be sure to say what, who and the P/N so others do not have to guess what you are doing/did.  There have been so many different topics covered here over the years, most things have already been run to ground.

[CapnDirk]

 :)rotflmao :)rotflmao   Or circuit breaker.


This must be the "short list" of humor.  But one of the many things wrong on mine was gauges that pegged to the right when the headlights were turned on due to a ground wire hanging loose.

[M & J]

Grounded in humor?

[DaveVA78Chieftain]

La, La, La

La, La, La

La, La, La, boing  i??

La, La, La

La, La, La

La, La, La, psssst   

Grounded?  Me?  Nah, MY fuses blew long ago   

[M & J]

Poor Dave.. SMH

[joanfenn]

  poor Dave, he has finally snapped