Unfortunately your gonna need a scanner to look at data.

You mentioned the issue and solution too. You need more power to start. It is definitely an electrical issue but figuring it out may not be that easy and probably cost a lot. If you buy a battery with higher CCA, it should solve the issue. 

I have a 2010 Pathfinder. I had the same problem. Actuator was draining the battery. 

This is my follow up to my previous comment and represents one possible fix that worked for me. That said, because the problem is electrical, the solution could be in many different places, such as the Actuator, as in MEK's situation, and so this fix may not be your fix. But it only cost me about $25 so you might try it before shelling out for a bigger, stronger battery.

I had already tested for and ruled out parasitic battery drain. I had also replaced that battery, as well as the distributor, alternator, spark plugs and spark plug wiring, within the last year, so the problem was not likely with any of those things.

The key is ambient temperature: Warm weather - car starts. Cold - doesn't start. Warm again - starts. Because batteries get weaker as the temperature drops a quick answer is a different battery with more Cold Cranking Amps (CCA essentially being a promise of minimum power available even at below freezing temperatures). Only at 800 CCA I already had close to the highest CCA available in a battery purpose built for my car. To get more CCA I'd have to 1) get a much more expensive battery that 2) was not made for the car and so 3) might require a mod to the car for it to fit. For example, I found 1000CCA battery but it was ridiculously expense and possibly twice as long as OEM (and probably made for a tractor or industrial machine). 

Because I couldn't imagine Ford designing an underpowered car, and where my starter motor still sounded strong and well fed, I concluded that the problem had to be in the wiring. As I said before, as cables wear, fray, or corrode, their conductive resistance goes up, which then demands more power to make them work. And the wires that corrode the fastest are the ones connected to that box full of acid.

With this in mind, at my auto parts store I bought:

1 High purity copper, 2ga replacement battery cable.         

1 two-pack of lever-clamp replacement battery connectors.  

1 two-pack of copper crimp-on eyelets.                                     

The replacement battery cables come in different gauges, lengths, and purities. I went with higher quality copper and 2 gauge (for those who don't know, gauge works backward, so 2 gauge is thicker than 4 guage) to give me the least electrical resistance possible. I almost shorted myself (literally) by buying the 24" cable rather than longer to save a buck. As it turned out it only just gave me enough to do the job. Any less and I'd have had to make another run to the auto parts store and buy another cable. (As a friend once said, it's better to be looking at extra cable than looking for it.)

For the replacement terminal clamps I went with the lever-clamp style with crimp-on eyelets that bolt to the connector, rather than the cheaper ones that pinch the cables together. Get what you like but I much prefer the lever clamp when working with the battery, and the extra length of the connector actually proved useful later on too.  

The Taurus has two lines coming off the positive terminal and two lines going into the negative terminal, but one of each of those goes directly to the starter motor. I'd already decided that was getting plenty of juice so I wouldn't have to replace those wires but the Ford original wires are cast directly into the terminal clamps so I would still have to cut them at the terminal clamp end and crimp on new eyelets.

First challenge: the factory original cables (especially the negative) are only just long enough to reach the terminal posts. Fortunately, my new lever-clamp terminal posts gave me back an extra inch, making up for the difference. Second challenge: when I peeled the jacketting from the end of the negative line from the starter I found a fair amount of corrosion. I scraped the bare part of the wire with a utility knife before adding the crimp-on eyelets but if I have starter problems in the future I might be replacing that cable next. Third challenge: I don't have a crimping tool. Fortunately, the eyelets that came with my replacement terminal clamp kit were still easy enough to install using lineman's pliers and I figured out a work around for using the additional copper crimp-on eyelet I bought. Just be sure to press really tight every time.

The other two wires coming off of the battery go directly to the fuse box and the car body respectively. I replaced the battery to fuse box cable first. The Ford original cable has a uniquely L-shaped eyelet, notched, but I only had to slightly modify the factory installed eyelet of my new battery cable to get it to fit. I then ran it to the terminal post, cut it to that length, and crimped on another of the eyelets supplied in the replacement connector kit.

Unfortunately, that left me only just enough cable left over, after cutting off the factory installed terminal end, to replace the negative-terminal-to-car-body-wire. This is where I used the extra copper crimp-on eyelet. I'd bought it with a smaller diameter hole because the screw to the car body was smaller. The crimp-on isn't very deep, though, and I didn't feel completely confident with what I could do with the lineman's pliers, so I used a small torch to melt some solder into it for a better connection. 

The other night the temperature dropped below freezing but the car started right up in the morning without any hesitation.

This may not be the complete fix for this problem but the thicker gauge wire, and higher quality copper, made a clear difference.