pulsed to steady cap values?

I'm thinking of building a pulsed to steady relay configuration for some future lights (LEDs) on my truck but I wanted to find out if anyone knows of some kind of chart or something that tells how long a capacitor will hold a charge for a regular bosch style 30/40amp relay? Intentions: Run 2 strips of LEDs down each side of my truck by the door sill steps (Entry Foot lighting), 1-White 1-Yellow. I'm not too sure of functions yet, I may have the white as a DRL/Marker light& Entry Light and the yellow as a turn signal, but I may just make the white entry only and the yellow as a turn signal. TIA, Ace_boy2099 edit: Also what voltage capacitors would I need? 16v 25v 35v etc?? is using the 35 just extra insurance or would that mess something up?

a 10,000 microfarad cap is pictured in the diagram. It will convert a blinker signal into a steady. You will not hurt anything using the 35 volt capacitor.

ok, I take it the uF number is the microfarad number? or is that a scaled number? So there wouldn't be any difference between the 16v and 35v capacitors used on a vehicle's 12v system, good to know thanks. How long of a charge would that 10,000 cap hold (how long)? how long would a 4.7, 470, 1000 hold?

I would stay away from a 16v device. A 4700 mic cap will not hold long enough to be functional. But if you want to find out, purchase 2 4700 mic devices, try with only one and then parallel the second one to make it work.

ok then, next question (Sorry I have so many), Where would I find a 10000uF cap of 25+Volts, The only thing I can find on a google search is from Jameco which is a 10000uF axial 16V 20%(and it's radial Counter-part I'd rather axial I though I think), Other than that all I can find is the 4700uF or smaller in the same (16V) and higher voltages; That is aside from one listing on eBay for 2-10000uF 25V Nippon Capacitors for $7.95+2.25 Shipping. also, Which way do the arrows on the capacitor point? to the positive or to the negative like a current flow?

The negative terminal will be marked.