About a week ago, I jump started someones vehicle. I know I did it correctly, but I still must have managed to burn something out in my alternator. I had/have about 50,600 miles on my 2013 LR4, so no luck with warranty. Land Rover Madison Wisconsin had a pretty piss poor customer service when I called. Dude even had a pretty strong british accent. He must feel pretty special working at a land rover dealership in the midwest. Anyway, talked to parts department just to get a part number (LR065246) and see what they wanted for the part... $909.27 ... I'll just let that sink in. So a friend of mine here in Dubuque owns a nice little euro/import car dealership, was able to find me a new Denso DAN1103 aka LR023421 (the box says RRS 5.0L, but same thing) It's an older part number, but from what I can tell the exact same manufacturer part. 150amp, etc. Got a new one, no core charge for $380 (with taxes and credit card fee). First the symptoms. On startup I would notice the voltage would kick up to 14v or so for a few seconds, but after that I could only get 13v+ by coasting downhill at a good pace. The rest of the time the voltage was ~12.3 or whatever the batteries could muster together. It shouldn't really be below 13v ever when running. The batteries where discharging at a good rate though. I would have had problems a lot sooner had I not had the dual AGM batteries and the traxide kit. I went a good week of town driving before I noticed the batteries where really getting lower than they should. The weather has been crazy cold and with all the heated seats, windshield, washer jets, steering wheel, and massive audio amps of christmas music through the 17 speakers.. i figured a little low might be normal. So, to do this yourself is not that bad of a job. If you can change brakes you can do this. A few tight spots but otherwise not horrible. Tools: You need 13mm socket, small extention, 10mm socket. I used a small torque wrench for the tensioner, you might be tempted to use a longer one or a long breaker bar, but the transmission lines are in the way near the bottom, so I used something a little shorter. I had a 1/2" wrench for my aux battery terminals. The OEM neg battery can be undone with a 10mm socket. The hammer is for putting the plastic clips back in. need nose pliers for getting them out. Voltmeter can be used to test if the alternator puts out 14v+ when its charging.. mine wasn't even putting out 13+. 1. Remove negative battery cable(s) from batteries. (you are disconnecting a positive cable off the alternator and you don't want to short that out to a negative/ground on the chassis.) 2. Raise the vehicle a bit. I used the front cross member and put jack stands on both sides. 3. Take the center front engine shield off, so you can see the front of the engine (From under) The big bolts are 13mm @ 45 ft/lb. The little ones are 10mm, not sure of torque, but not 45, just hand tight. 4. Take the passenger side plastic panel off so you can get access to the alternator. It has 5 of those pain in the ass plastic rivets. You have to pull the center out (or all the way out) and then the base will come out. I could only get 3 out intact, so to ebay for more! http://www.ebay.com/itm/261961115575 5. Now you need to take the tension off the serpentine belt to get it off the alternator pulley. Once you do, it will most likely come out of place on the other pulleys also, but just be aware of that and make sure they all get put back into place when you put it back on. It isn't very difficult to check that. 6. Next you can undo the red electrical cable (~9ft/lb) and the 3 other bolts. All are 13 mm. The alternator bolts are 35 ft/lb. 7. When you get that loose you have to take the electrical connector (the pulse width modulation "PWM" signal cable). It just has a largish flat side which you push in and it should come out. Be careful with the weight of the alternator as you do this.. that signal line is one little gauge cable. you don't want to bust it.