K put a new battery in last summer, wasn't a great battery but due to circumstances. Only one I could get. Anyways idk how accurate a scan gauge 2 is but i'm running at 13.4 to 13.8 volts. to me that sounds a lil low and I took a look at the alternator and it looks like its original. Am I just a lil paranoid or anyone think in the near future I'm gonna be needing a new alternator? Found with these vehicles the preemptive strategy is always the best way to go.

 

I responded to this in the other thread.

 

Ha I erased it there cause I accidentally put it in a reply on another thread

 

Okay. I guess I have to type it again.

If you're getting that 13+ volts with the engine running and accessories on, your alternator is doing okay. If you want to really test the alternator, turn the engine one and turn everything on. Turn the radio on and all the way up, turn the headlight high beams on, turn on the windshield wipers, turn on the heated seats (if equipped), turn on the a/c, then look hook up a voltmeter to the battery and see what your voltage is. If you're over 13 volts, you're good, if you're below 12.5 volts, there may be a problem with the alternator.

 

At idle with just minimum on 13.8 OK. As more things turn on, load increases, volts drop slightly. With everything on, should still make 13.2 volts. Below 13.2 you are not fully charging the battery. An alternator with a blown diode will drop off as soon as amps increase above 2/3 capacity, sometimes 1/3 capacity. See https://landroverforums.com/forum/ge...or-amps-46591/

 

Thanks guys for the info, much appreciated.

 

This is not accurate information.
With a fairly good 800 CCA rated battery your voltage has to be above 13.6, up to 14.4, any less and you will have low voltage issues.

 

I don't think I've seen a Discovery go that high with everything on. I don't think I've ever seen one pass 13.5 with everything on high. At least not one with the premium sound system and heated seats (which is all I've ever done that test with on the Discovery). With everything off, of just one or two things on sure, but never with everything on full blast (high beams, wipers (front and back), radio (blasting), heated seats (both of them), a/c, blower (on high), hazards, etc. The only way I would believe it would still pump out 14 volts under those conditions is if I saw it my self, or maybe a video.

 

Then you have not been looking at a very good charging system.
Those are the proper numbers to be used when checking out a charging system.
Currently, when off, both my Yellow Tops hold between 12.65 and 12.75 volts and at idle my charging system sits at 14.35 volts, as of last week.

 

I've looked at several charging systems. I know not all of them are bad. Those numbers are normal, for a car that isn't under a load. Start turning things on and that 14.35 will drop significantly.

Shoot a video. Attach a voltmeter, show the voltage, then start the car and show the voltage, then turn on the high beams, both sets of wipers, turn on the radio and turn the volume all the way up (music with some bass in it), turn on the heated seats, the heated windshield, the hazard lights, the a/c, and turn the fan to max, then show the voltage on the voltmeter. If it still reads over 14 volts, then I'll believe you (giving you the benefit of the doubt that you didn't edit the video). Until then, I stand by what I typed earlier... As long as you have over 13 volts under a full load, your alternator is fine.