I'm going to go out on a limb here and say you probably toasted your under the hood fuse box. You can remove 3-4 screws and lift it up, and examine the wires underneath it. You can grab them online from Ebay pretty cheap and it's PNP as long as you get the same model year or 99-02 vs 03-04.

If you didn't melt the under the hood fuse box, then check every single fuse/relay in it.

 

Wow.

I replaced the 10A fuse in the engine compartment fuse box, which I assume is the one guarding the BCU, as it was the only blown fuse, and my baby started right up! My mind is blown. I've been stuck at work over Christmas and haven't been able to even start checking stuff till tonight. While at work, I called my insurance and found out towing is covered under my policy, so had it towed home on a flatbed.

Only two problems left:
1. Battery light is on after the car starts. They replaced the battery I reversed polarity on, as it wasn't blown, and I got the correct terminal configuration this time around, so since this battery is brand new,, I assume the light means the alternator is fried. Especially given the small trail of smoke I saw. So can I repair that sucker? I've seen some threads on complete disassembly and some on repair.
2. Radio won't come on. Any way to test the components to see if it's fixable, or just dead?

Otherwise, everything works. Seats, heated seats, A/C, windows and sunroofs, lights, key FOB.

Thank you, thank you, thank you guys for all the great advice and ideas. You gave me so many leads, and I was armed with ideas because of you.

 

How is roverlandparts.com? I'm reading mixed reviews. You think I would be safe to buy an alternator from them? Hard to turn down at just $118 compared to $450 at Atlantic British.

 

I've heard of folk getting alternators rewound for much less $ than a replacement. I've never had to tho so can't comment in where/how.

I would at least have the alt confirmed dead by an auto parts store testing it.

Radio could be just a fuse in the head unit itself. They often have a visible fuse on the back of the unit, or Ive seem some with fuses inside the unit.

I assume you've tested each small fuse on the board inside the car one by one?

Edit. Oh, congrats on it not being a complete holiday downer.

 

Use a coin to unscrew the two plastic screws under the steering wheel, revealing an interior fuse box. The fuses for the radio and related stuff are in there, I believe 15A fuses at the bottom left – they're probably blown.

I wouldn't think about replacing or rebuilding the alternator until you've fully diagnosed it. Check your codes again, which might give you some direction.

 

Ok, so I went ahead and got that refurbished alternator for $120, because it sounds like the alternator shop in town might cost as much and take a while; trying to get up and running quickly. Once I swap the alternators, I'll take the (presumed) fried one to the guy and probably have it repaired for a back-up,m. Also was worried about driving to an Auto Zone with no alternator to have it tested, so I'm just assuming it's busted.

No codes anymore, just the battery light.

I'll get to the radio once the car's working again.

That viscous fan is killer—the hub is stuck. I didn't want to break anything so I went ahead and ordered these two parts ( https://www.amazon.com/gp/aw/d/B004N...?ie=UTF8&psc=1 )to get it off, so that'll set me back a few more days.

A few discoveries:
1. I was using battery post shims for my severely loosened battery cable clamps, but upon installing the new battery, I discovered I could use my channel lock pliers to squeeze the clamps tight again and voila! no shims necessary.
2. The upper inside of my radiator has a series of about six inches of those metal fins that are flattened, I'm guessing from the last time someone took off the viscous fan. I've had a slight coolant leak I haven't been able to identify the source of, think this could be it?
3. My viscous fan doesn't have a protective plastic ring around the outside of the blades like in all the pictures I've seen—is that all right?

 

03-04 D2 fan clutch is a one piece unit with the fan attached. If you plan on running a Hayden fan clutch u will need a fan blade out of a 99-02 D2. Then u can install a fan clutch.

Auto Zone can test the alternator while in/out of the car. They also rent the 36mm fan clutch removal tool.

 

Oh so you're saying that's just how the 03-04 fan clutch is? Gotcha.

You just saved me some good cash Best4x4, I called them and sure enough, they've got it at my local auto zone. Cancelled my order. Thanks for the tip!

 

Not sure if this arrived, but the wrench won't fit, you need a 36mm. The craftsman fan clutch tool is on Amazon and it works for sure.

Edit- saw you cancelled your order. Autozone does not have the pulley holder though.

 

You don't need the pulley holder 99% of the time. To remove the fan clutch from a LR D2, remove the fan shroud by loosening the 4 screws, then take the 36mm fan clutch wrench and place it 12oclock position (may have to rotate the fan blade). Then take a slow blow hammer or small sledge hammer and hit it down. It may take several times, but it should come loose. Then just spin the fan clutch off making sure to hold it so it doesn't fall into the radiator.

Now since you have an 03-04 Model you CAN NOT reuse your 03-04 fan blade with the 99-02 D2 fan clutch. You must either purchase one new online or find a good used one at a salvage yard. Then just slap the new fan clutch onto the fan blade and you're all set and now you can simply change out the fan clutch vs the entire assembly.