I've done a bit of Googling and can't quite figure out the answer.

The scenario is:
I have a battery isolator which has two leads that are used for a LED status indicator, and another for a momentary circuit (which bridges the batteries together).
Instead of getting a off the shelve LED pilot light, and momentary switch, I was thinking of trying to use one of the factory momentary switches.

I've got one of the defrost ones (the square one by the hazard button). ***EDIT*** Actually it is the Heated Windscreen Button. http://landroverparts.roversnorth.co...code=YUG102550

The documentation for the two leads on the battery thing say
Optional circuit connections:
a) Connect violet “Boost” wire to a normally open momentary switch. Connect the other side of the switch to +12V DC.
b) Connect white “Status” wire to a 12V DC, 50mA max. audio/visual alarm. Connect the other side of the alarm +12V DC.

So..
I'm trying to connect the "Status" wire to the defrost switch so the amber light illuminates.. Which PIN would that be?

I'm also trying to connect the violet "boost" wire to the switch, so when I mash the defrost button it triggers this boost wire.

Secondarily, which PIN is the ground, and which is the dimmer backlight?

Thanks

 

Ok.. Did a little debugging on the current defrost momentary switch.
Pin 1: Normally 1.2v... when depressed goes to 0v
Pin 2: Backlight (when lights are on)
Pin 3: unused
Pin 4: Grnd
Pin 5: Amber LED, 12v+ when switch is activated.

So I'm good with Pin 4 and Pin 5 for my "status" light. Now I need to figure out how to get Pin 1 to be normally 0v and 12v when pressed. Or is there a different factory momentary switch that others know about that does this?

Thanks.

 

just a guess but I would think the factory monetary switch opens and closed a relay?

 

Yeah, I think your are right... When I press the button, I can hear a relay click active under the dash.

I need to think about this a little more

 

See page 83 of 152 in the circuits manual for heated front screen. The switch connects to the BCU, and the BCU operates some relays.

Pin 4 is shown as earth ground, pin 5 is lamp drive from BCU, pin is the "sense" lead from the BCU, pressing the switch grounds it. I think the BCU only heats front screen for a certain period of time, not burning hot forever.

On page 107 of 152 they show the light for the switch, +12 from dimmer on pin 2, earth ground again on pin 4.

So you could re-purpose the switch, but will need to cut up the harness a bit. One way around that is unplug switch, and use a connector from a donor vehicle with your new wires on it.

Please fuse until it quits smoking and burning. Have to add your own relay, to make the +12 when pushed.

Pages attached.

 

Thanks for the pages and tips Buzz.
I have a new switch from a donor vehicle.
So... i'm trying to think how this would look.
Pin 1: To Relay (which when pushed, opens the relay?) Which relay should I use?
Pin 2: Dimmer (if I want to)
pin3: nothing
Pin4: grnd
Pin5: white "status" wire from battery isolator

Really it is the purple "boost" thing that I am trying to function with the momentary switch.

I'm not an electrical wizard, so any napkin drawing you might be able to provide would be excellent.

I've attached the instructions for the Smart Isolator, which I managed to get everything wired up and functioning properly... just need this "boost" thing wired to the switch

I also attached the "how-to" on how this isolator works... its simple, but the how-to provides easy to understand pictures

 

Problem solved... No relay required.
PIN1: Purple "Boost" wire from Smart Isolator
PIN2: Light dimmer (brown/red wire from another switch)
PIN3: unused
PIN4: White "Status" wire from Smart Isolator
PIN5: 12v + (from anywhere)

Since I've spent quite a bit of time on my wiring, I drew it up in a diagram if others are interested.

I use the Painless Wiring Box as my central "hub" for my accessories. This way I don't have rogue inline fuses all over the place.
Painless Performance: CirKit Boss®™ Auxiliary Fuse Block/7 Circuits/Weatherproof

The diagram shows two constant hots feeding a pairs of lights (actually a relay) that powers the lights. I have two sets of this configuration, I just couldn't fit on the picture. I have the 4xHella 4000s on the roof... Configured so the Outside set and Inside set are on seperate switches, fuses, and relays.

The Engel fridge and CB radio share a different "constant" hot circuit. No switch, just straight to a 12v cigar plug ran to the rear of the truck.

There is a 3rd set of pencil Hello 770F (i think) on the bumper which are fed by a seperate fuse, relay, switch. This set is on an "ignition" hot circuit. A 2nd "ignition hot" circuit feeds a 3-way 12v cigar outlet under the dash to feed 2xGPS (one topo and one road navigation) and Sat Radio

A seperate "ignition hot" feeds those cool LED running lights someone posted a while back. That way they come on and off with the truck.

The dual battery setup is using this Smart Isolator. Which can be found online for about $100
Battery-Related Products | Battery Isolators48530 | Cole Hersee - Littelfuse

I have a Redtop starting battery, and a Yellow Top "house" battery. The Yellow top feeds the Painless fuse box..

My winch is connected directly to the Yellow Top posts.

Hope this info can help someone else in the future.

 

Nice diagram. Do you have any pictures of your setup or is everything hidden?

 

All hidden... I will try and snap some pics of some of the "guts"
Only thing visible are the components. IE: Sat Radio, GPS1, GPS2, UltraGauge, Switches

 

Pics.