Ha! Wow, thanks for all the work searching around. I'd be more than happy to pay someone to piece it together if the price was worth it to both parties.

With your idea of having both the ON and OFF delay, is the wiring going to be complicated? Am I only going to need the 2 wires I currently have going to the LED? IE: The 'switched' Ground wire & the 12v power wire?

 

No it won't be simple.

You will need +12, grd, wire from tank, and led/resistor connections.

The only simple way was my first suggestion, although it seems it will not perform for you.

I couldn't imagine anyone prototyping a circuit for you for less than $100. But hey who knows.

Seems 12vdc time on/off delays are asked about so much, it may pay for someone to make a few up.

If I get that bored I'll let you know.

 

Alright. Maybe I should take a step back.
Let me try to get clarification about whether an ON delay or OFF delay is what I want to prevent the LED from coming ON until X amount of seconds after the 12v becomes HOT.

In my setup the switch terminates the Ground wire. So the LED has the ground from the switch which is NOT terminated most of the time. Then it has the 12v lead which doesn't go 'HOT' until the ground is terminated from the switch.

SO, if I want to delay just the ON event, in my setup, where the ground isn't always terminated & power isn't constantly on (until the switch terminates the ground to the LED).

Which should I get, an ON delay or an OFF delay, to keep the LED from coming ON until X amount of seconds after the switch terminated the ground which makes the 12v HOT.

It seems like an ON delay is what I'd want, but I want to make sure.

THANK YOU!

 

Easiest way to make an ON-delay with indication is to have the 12V do supply a CD4093 (four schmitt-triggers in a 14p housing) via a resistor in to pin 1+2, link together pin 3, 5,and 6. On pin four You can put a resistor (4K7) in series with an ultrabright LED.
Between pin 1+2 and pin 7 you must have an capasitor of some uF.
The 12V must in addition be connected to pin 14.

Now You have a compact Delay-on cirquit wich is trimable to almost any delay You want.

With the resistor between +12V and pin 1+2 of 82K and a capasitor of 470uF You should get around 30 seconds delay.
Smaller cap and/or smaller resistor will shorten this time delay.

If You would like to have anything powered from that cirquit, there is several ways to make this happen.

What device do You want to be powered?

I can draw it up for You if You like.

 

Easiest way to make an ON-delay with indication is to have the 12V do supply a CD4093 (four schmitt-triggers in a 14p housing) via a resistor in to pin 1+2, link together pin 3, 5,and 6. On pin four You can put a resistor (4K7) in series with an ultrabright LED.
Between pin 1+2 and pin 7 you must have an capasitor of some uF.
The 12V must in addition be connected to pin 14.

Now You have a compact Delay-on cirquit wich is trimable to almost any delay You want.

With the resistor between +12V and pin 1+2 of 82K and a capasitor of 470uF You should get around 30 seconds delay.
Smaller cap and/or smaller resistor will shorten this time delay.

If You would like to have anything powered from that cirquit, there is several ways to make this happen.

What device do You want to be powered?

I can draw it up for You if You like.

Well... I am feeling like I may have posted in the wrong place. This is clearly for people who know circuits! Which I know nothing of! HAHA!

I think I'm likely just frustrating anyone trying to help since I'm a complete newbie. Another reason I was hoping for links to devices that are already made to suit my needs.

Unfortunately OP has rejected all TD-on and TD-off solutions.

Something like this may work, but OP needs help with construction and wiring.

http://forum.allaboutcircuits.com/showthread.php?t=94281

I'm not sure I follow. I'm open to time delay on or off solutions. I'm just not sure which one I need & I threw a curve ball asking if I should use an Time Delay on & off device.

Don't get me wrong. I'm a DIY'er. But building this from scratch would take a great deal of coaching and I think it would be easier if others could tell me if I need an ON or an OFF delay timer, and then linked me to some options so I can just buy one that's already made.



Sorry, I'm getting the idea you guys are use to electrical engineers posting & knowing what you're talking about. Hehe

 

Alright. Maybe I should take a step back.
Let me try to get clarification about whether an ON delay or OFF delay is what I want to prevent the LED from coming ON until X amount of seconds after the 12v becomes HOT.

In my setup the switch terminates the Ground wire. So the LED has the ground from the switch which is NOT terminated most of the time. Then it has the 12v lead which doesn't go 'HOT' until the ground is terminated from the switch.

SO, if I want to delay just the ON event, in my setup, where the ground isn't always terminated & power isn't constantly on (until the switch terminates the ground to the LED).

Which should I get, an ON delay or an OFF delay, to keep the LED from coming ON until X amount of seconds after the switch terminated the ground which makes the 12v HOT.

It seems like an ON delay is what I'd want, but I want to make sure.

THANK YOU!

Yes an on delay.

 

Would this do it or would there be one that would be more simple with less wiring required?
http://www.ebay.com/itm/350682044369?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

How would I wire this one in when I only have 2 leads, the ground from the low level sensor and the 12v lead from the cars power.

Thanks a million yet again!

 

Would this do it or would there be one that would be more simple with less wiring required?
http://www.ebay.com/itm/350682044369?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT

How would I wire this one in when I only have 2 leads, the ground from the low level sensor and the 12v lead from the cars power.

Thanks a million yet again!

Those two leads would connect to the plus and minus input leads. Shown on the left in the right hand picture.
That simple!

The other pins are "switches" that will open or close, after the tank switch has been closed, for the set time.

Keep in mind that slosh opening the switch, will turn indicator off immediately, for the set time.

Delay-on, delay-off, it's 6 of one, half dozen of the other. The other way will be immediate.

The timer suggested in post 13 would serve just as well. IMO
As would the simple fix in #8.

 

The other pins are "switches" that will open or close, after the tank switch has been closed, for the set time.

Keep in mind that slosh opening the switch, will turn indicator off immediately, for the set time.

When you say tank switch closed or opened, does closed mean the ground from the switch is terminated (turning the 12v power on), and open means the ground from the switch is disconnected (turning the 12v power off)?

I figured the other solutions would likely work too, I picked this one cause it offered an adjustable time up to 60 secs right out of the box.

I think I finally found the solution I've been looking for. And it's cheap! Thank a ton guys.

 

When you say tank switch closed or opened, does closed mean the ground from the switch is terminated yes(turning the 12v power on), and open means the ground from the switch is disconnected yes(turning the 12v power off)?

I figured the other solutions would likely work too, I picked this one cause it offered an adjustable time up to 60 secs right out of the box.

I think I finally found the solution I've been looking for. And it's cheap! Thank a ton guys.

Good luck, let us know how it works.