I have a 2008 lr2 with 55k on it. Last week while driving the battery light turned on and it eventually lost power and shut off and wouldn't jump start. I charged the batter with no change and then went ahead and replaced the alternator. With the new alternator in still wouldn't start it wouldn't even crank. So i replaced the starter and now it starts but the battery light is still on. The voltage shows 11.96 so i got the alternator tested and it shows no voltage when in the car. Naturally i took it back and they swapped it for another one and installed it but again no voltage. I should point out last november i had the wiring harness replaced under the suspicion it was faulty but it turned out to be the ecm. When it starts now it makes this weird somewhat screeching sound. Any ideas? I'm thinking maybe the belt but don't want to rush to that.

 

Are your mechanics sure the alternator is actually spinning? The alternator is driven by a coupler, driven by a pulley. That pulley fits on a tapered spindle and when the nut looses torque, the pulley stops spinning, or spins very slowly. If you remove the alternator, you should NOT be able to spin that pulley by hand. Also make sure the rubber coupler isn't worn out.

 

i will have them verify it. I know it looks like it is spinning but i will make sure

 

If you know for sure the alternator is spinning at the proper speed, then you may have a wiring issue. The output of the alternator is controlled by the Engine Control Module via a dedicated LIN Bus. If that wire is damaged or the connector isn't fully seated, that could also cause this.
What brand alternator is being installed? are ALL the fuses good?

 

it is a duralast gold alternator as far as fuses i checked all the ones in the three fuse boxes and only found one blown which was a cigarette lighter. is there another fuse i should be looking for? I'm not sure about the wiring being bad being that i put a new harness from LR in last nov and it ran great until last week. How fast should the alternator be turning? It does seem like the drive belt is turning faster than the alternator is turning. I should mention i was told than when the original alternator was pulled there is a bolt in the middle of the coupling that was loose. I don't know if that makes an issue.

 

You are probably talking about the bolt that holds the coupler pulley to the engine, see picture:

LR2Charge.jpg

This bolt has to be torqued to a specific torque value and you may want to consider some Loctite on the threads. I hate to suggest Loctite when service info doesn't call for it, but I had one back off a year after torquing it once.

 

so I suspect it may be that pulley. it spins easily by hand the only issue I have is when I try to tighten the bolt the drive belt turns so i'm just spinning it rather than having it continue down the screw post to eventually tighten

 

Any update on this?

 

so what I ended up doing was using shorter bold since the one that was in there I couldn't get in all the way causing it to be able to be spun by hand very easily. added the locktite and secured it and it has been running fine so far

 

Hello and thank you, the car has 149k, I live in a very moderate climate in central USA Michigan. The engine before the belt breaking it was running great no problem, the car lost horse power only after replacing the pulley and serpentine belt.