Can you give us a basic diagram of what you're working with?

Here's what you've given us to work with (in part; post #6)

As I understand it, ACC is active when the key is in an ON position. From what you just said
I must admit being confused.

If you have constant power (unswitched) from the battery then wouldn't you have a condition where your LED's are on all the time? This is why we need a drawing of what you are attempting to accomplish. Even if you have to scribble something on a piece of paper and take a picture of it and post it - at least we have somewhere to start from.

there are 2 batteries each severs different loads across fuse boxes. - the backlight would operate from the ACC, however load on/from the switches are dependent on the the fuses supply of power, which are constant power. But of course only send power the load device when switched.
backlight would be from the Acc power whilst dimmer circuit would be dependent upon lights (on/off)

 

OK, I'd like to be able to help you, but what started out as a simple question has become more and more complex as we have to guess as to what you're trying to do. It's taken this long just to learn you have two batteries that supply power to something (as yet we still don't know what, how or why). Now it sounds like you want the ACC to activate the ability to control these loads, but I just don't know exactly what your goal is. Until I can fully understand your needs I can't help you any further. I could sit here and draw pictures all day long and eventually come across what you want, but I'm just not willing to invest that much time and effort into your project. Far as I'm concerned, I've answered your question, the one you opened with. I've gone beyond that to give you understanding on how to switch colors. Even given you a way to automatically switch between daytime brightness and nighttime. I can't keep sitting here engineering your project. I like helping but there's a limit to how much I'm willing to do. I'll help you but I won't do it for you.

Give us a drawing detailing as much as you can and maybe we can help. But without further input from you along with what you want it to do and how you want it to behave, I'm done guessing.

 

FAIR

OK, I'd like to be able to help you, but what started out as a simple question has become more and more complex as we have to guess as to what you're trying to do. It's taken this long just to learn you have two batteries that supply power to something (as yet we still don't know what, how or why). Now it sounds like you want the ACC to activate the ability to control these loads, but I just don't know exactly what your goal is. Until I can fully understand your needs I can't help you any further. I could sit here and draw pictures all day long and eventually come across what you want, but I'm just not willing to invest that much time and effort into your project. Far as I'm concerned, I've answered your question, the one you opened with. I've gone beyond that to give you understanding on how to switch colors. Even given you a way to automatically switch between daytime brightness and nighttime. I can't keep sitting here engineering your project. I like helping but there's a limit to how much I'm willing to do. I'll help you but I won't do it for you.

Give us a drawing detailing as much as you can and maybe we can help. But without further input from you along with what you want it to do and how you want it to behave, I'm done guessing.

fair point, not too good at diagrams but i gave it a shot.

very simplified diagram but gives and overview of the most relatively 'complex' of the setup.

notes -

• power sources are starter battery and Aux battery
• long or heavy loads (fridge/ amp etc..) pull main power from AUX battery - an i just noticed a mistake in the diagram already - power to the aux load switch must also come from the aux battery- as once acc. is off the relay will cut power to the fridge - so addendum ...
• with that said - the simple SPST will energise this load and would make sense (given minimal power draw) to illuminate the whist powered
• acc load will run to switch in this case a SPDT where as the light will energise by switching on , but also when switch the the other on position be triggered by hi-beam. this means the normal power in becomes the common power out (to light) - bit arse about but does indicate a twist on the theme

 

not too good at diagrams

Being modest? That's a pretty complicated drawing. Better than what I would have done.

Now I'm getting a better idea where you're going with this. Can you include (in block form) the circuitry you want to add?

Block form means simply drawing a box or block with a single wire showing that this is connected in some way to something else. I'll post a drawing here in a few minutes depicting block form diagrams.

 

Re-reading your last post, I'm thinking you just want the auto electrics to control the backlighting of your switches. From your diagram it looks like you have the rest of it figured out. If so - you may have to upgrade from SPST (or SPDT) to DPDT. I'd go with DPDT. That way you can isolate your deep cycle battery from your automotive electrical system. All the DPDT will do (via one side) is control your power to your load and the other side will control the LED's which are powered via the auto electrics. I think with that definition you're where you want to go. NO ? ? ?

 

Well, here's my last stab at this. The drawing shows a control panel with multiple switches. IF you want multiple switches you may have to live with the BLUE LED being on all the time. If so then you can use SPST switches. If you want to kill the blue LED then you'll have to go with DPDT switches. Multiple switches presents further challenge in controlling the blue LED. Perhaps daisy chaining switch to switch to carry the blue will work. Interrupt any part of that chain and the blue goes away.

Nevertheless, the diagram shows the control panel receiving power from two sources. B1 is the auto electrical system and B2 is your deep cycle battery. I did not address how you're going to keep it charged, but that's a problem you probably have already figured out. This goes back to my original premises that if you want to control the brightness of the LED's you can opt to use the resistor circuits I've drawn previously along with the additional relay to switch from daytime to night time brightnesses.

Hopefully this addresses all your issues satisfactorily. Sorry, but you're going to have to fill in some of the missing pieces.