Adding ditch lights to Kato SD40-2 with NCE N14K1

[Southern1970]

Hi all,
Apologies if this topic has already been covered.
I’ve seen a video on YouTube (haven’t we all) where a guy had installed a TCS decoder into a Kato N scale diesel locomotive.  He then soldered prewired 0402  smd leds to the function pads on his decoder and cut the light leads to the separate ditch lights (so he could then program them separately for the head light and have the ditch lights blinking alternately.
I don’t have a tcs decoder for my SD40-2 (mid production), but the subject decoder (I’ve attached a photo).
The decoder has F1 & F2 pads about the middle of the decoder.  Do I assume these are the function pads for lighting (as I could not find this detail in the decoder manual)?
If so, then are the closer pads to the front of the decoder positive and the ones closer to the back negative?  Is the function pad output 12v or does it have a resistor installed for lighting with Leds?
I have some prewired 0402 white Leds (I tested with a 3v coin battery).  Would I need to put a resistor on the positive side?
Any help would be greatly appreciated.
Cheers

[ns737]

on the board it looks like there are two resistors going to those pads. I think the back two pads are neg.

[peteski]

I would really like to see a closeup photo of those 4 pads to be 100% sure, but from what I can see (like ns737 said) looks like there are resistors on the left of the pads, so you should be able to attach the LEDs directly. However, having extra resistor would not hurt (but the LEDs will not be as bright.

Also, in series-connected circuits (LED and resistor are in-series) the location of the resistor (positive/negative side of LED) is irrelevant.

TCS documentation is really crappy (in documenting features is crappier than Digitrax, which to me has the most poorly written manuals). Other decoder brands (like ESU or ZIMO) have much better documentation, but they have limited decoder selection.

Also, this question would have been better posted in the DCC section of the Railwire, but I know: you're a newbie.