Scenario: Driving home from work, merging onto highway traffic, passing gear working properly- tach went up, then down to zero (engine still running,) battery light came on, UltraGauge voltage dropped to around 9v with A/C blasting. Interestingly, the SRS light came on as well, but went out after about five minutes.
The truck made it home without incident, lucky for me as it was about a 35 mile trip. With the A/C off the UG voltage varied between 10~11 volts. No blown fuses that I could find and, somewhat puzzlingly, no trouble codes, pending or otherwise.
Diagnosis: Dead alternator, or very close to it. The battery still measured just slightly above 12 volts, even after driving it home. I did try the old trick of disconnecting it with the car running, just to see if the alternator would sustain it. Although with newer computerized vehicles I honestly don't know if this even applies anymore. (The truck did shut off.) It seems the best case scenario is the brushes have become too worn to send any pulses to the tachometer circuit, but are just barely enough to trickle charge the battery. In any case, I might get lucky enough to have a local parts store stock a replacement. So tomorrow I get to post the resolution in the "What Did You Do To Your Disco Today" section, hooray.
And, yes, I realize that pretty much any alternator I get from the major parts chains will, in fact, be crap. But I don't have a second vehicle, nor the time to wait for a Bosch, unfortunately. (Or whatever the choice brand may be.) I might try and score one from the boneyard next time I visit, just to keep a backup handy.

 

Get one with a long term warranty and save the paperwork. Reman may not last long.

 

It is bad and they are french crap do like buzz said, big chain store life warranty

 

Just got one from autozone.com (got a 10% discount on the part by ordering online) Delivered in 2 days & returned the used part to the local autozone for the core charge. You will be amazed what wonderful things will happen when replaced as it solves a few other issues I was experiencing.

 

I'm off to get O'riley's finest: Ultima
Hey, if it gets me to work & back until I can order a better one, I'm happy. Like I said, it'll eventually become a spare.
Still curious, though... when something like that goes bad one would think it would throw some sort of code.

 

Weak battery does not throw a code. You experienced the "reserve minutes" of the battery that got you home, without AC it has greater range. The "alarm" is erratic and loss of tachometer, driven off that small flying lead. Be prepared for a failure within 2 weeks, mine did. I think this is attributed to cheap parts from LandofPanda, where quality control is not up to other places. You will note the fan cowl has a bump that direct radiator air blast into the alternator. Parts in there have to take the heat, it is a tough neighborhood.

UG was telling you the truth on the voltage, minus some connection diodes voltage drops inside. Volts at the battery would have been a fraction higher.

 

just had the same problem with mine. new battery and alternator. the gauges quit working along with other things if your not supplying a true 12v. sometimes they wont shift out of park either. there is a land rover junkyard off exit 10 on 400

 

What is the name of this boneyard of green oval delights?

 

East or West? A junkyard devoted to Land Rovers!? I must find this place of wonder!
Anyway, new alternator is in. Initially the voltage was all over the place on the UG but seems to have settled down to normal. (Engine computer acclimating itself to an organ transplant after battery disconnect?) Also, it may be my imagination, but the truck seems to run a bit quieter and idles smoother now.

 

Good to hear it. Now as for that boneyard, must be valet parking in that neck of the woods.