Hey guys,

So I picked up an 05' LR3 to go along with my Disco 11. Got a pretty good deal on it, super clean. It's got a few issues, but what LR3 doesn't. I noticed that the engine is really loud when I start it up and stays loud. It's the fan running. I remember when I had my Range Rover Sport that the fan would run for a about 10-15 seconds after you start the car, but would eventually stop. This LR3 is stays running no matter what. The battery seems good. I get 12.7 volts when the vehicle is off (at the battery). When I crank up the vehicle I get about 13.59 volts (at the battery). I know most vehicles get closer to 14.4 volts, but it seems like Land Rovers are all over the place. I've read that the fan running all the time could be an indication that the alternator is going out or something is wrong with it (diode or something). Every now and then when I go to crank up the vehicle I'll get the red battery light, but it will normally go out after driving for a few minutes.

Like I said it's got a few issues. Special programs not available, the D on the gear shifter stays lit up red weather the car is on or off, which I'm troubleshooting. Also the Terrain Response **** does not work (no lights, and nothing happens when you rotate it around to the different modes) and the sport mode shifting does not work. I know a lot of gremlins arise because of the charging system, so I want to eliminate this first. Any insight would be appreciated.

 

13.5 is low. Ideally measure the voltage at the alternator. While you're there, you could also check the alternator output for any AC current using a fluke. If the alternator is good you shouldn't get any AC current. If it is the alternator/battery, you may find that sorting those issues cures others. I'd certainly do nothing on the other issues until you've solved for the alternator/battery issue.

 

Dumb question... How do you test the voltage at the alternator. it's buried down there. and trying to get underneath while it's running... it sits pretty low. Do you test at the red boot?

 

You can access the alternator really easily if you take off the plastic guard underneath the passenger side of the car. Its held in with 4 trim retaining clips that you can pop off pretty easily and it gives you straight access to the alternator.

 

There's a really excellent youtube post by a Jeep owner who made an amp clamp out of bits laying around. He walks you through it. I'll try to find it later on youtube, but it's a really great way to properly test the alternator without having to use anything other than a fluke and some cable and clamps. The AC check is to determine whether the alternator is on the way out. Checking voltage at the battery is not a reliable indicator of the alternator's performance. You could also take it to a decent indy shop and have them check it for you (so long as they don't just check the battery...). As was said above, the alternator isn't hard to get at on the D3. If you decide to replace the alternator, then look at Denso. Some had bothered to replace the diode pack (if that was the problem) cheaply and ended up with a spare. Never tried it myself but an interesting project.

 

So, from my alternator I'm only getting 13.6. Looks like I'm gonna need a new alternator.

 

13.6 is where mine operates. I only get 14+ after the truck has been sitting for a while or during colder temperatures. The alternator is regulated so its output is based on factors like battery charge level and outside temperature. Colder means higher voltage output - but of course that drops as the vehicle is driven.

 

Do you get a battery light when you start up? I get a battery light on whenever i crank it up. It will go out once i get the rpm’s up over 1500. Also, does your fan run constantly? Curious, maybe its something else.

 

Ideally - if you can do it or get it done - you'd check the amperage as well before diving into changing it. I found the link to the homemade amp clamp:

 

Just swapped out the alternator. Immediately the idle dropped from 1100 to about 650-700 and the fan is not blowing. I'm getting 14.4 volts to the battery now. Thanks guys for your input. I was looking over the old alternator, it kinda looks like the one that goes in a v6 model lr3. It looks different than the one I bought.