Noticed today that I was only reading between 12.4 and 12.8 which seems low as most cars I've had stay steady in the 14s. Could the obd port not be accurate, or is something wrong? I will test at battery terminal tomorrow if I get a chance, but am wondering if there is an issue. The alternator looks like a newish Bosch replacement

 

Mine match. Just checked. If your figured are with the engine running that's low.

 

Thanks for checking, I had a feeling since I've usually had pretty dead on readings using the same method on my other cars. I'm not showing any codes related to low voltage, but am wondering if it can be contributing to my three amigos issue. The car does have a zillion miles so it's feasible that even though the alternator was replaced at some point that it could need one again

 

It can and I can do one better. A bad battery (and soon later, bad alternator) cost me a new transmission many years ago (out of warranty) by a shop that allegedly specialized in land rovers. It is out of business now. I was getting three amigos and eventually limp mode, and the same happened shortly after the new transmission went in. It was the battery and alternator. I had to figure it out myself.

You never forget things like that!

 

Wow! These things are odd to me, so primitive in some ways yet so complex in others. It seems like everything that doesn't involve the electrical system is super easy to work on. Hopefully this is a simple case of a weak alternator or bad ground. Funny thing is the car starts fine, and most everything works besides the power locks. Wondering if that may be related as well. I hear a click when I press the switch like a relay actuating, but maybe it doesn't have quite enough kick

 

It is possible, but the lock motors do go bad. You can try cleaning and lubricating them but in my experience when they start acting up it is time to pull out the wallet. They are absurdly expensive and with only one keyed lock it is a pain in the butt when they don't work. The worst are the back doors. You break your arm trying to reach the release.

 

As Charlie says, the lock issue probably isn't related to the low-voltage issue. The actuators in these trucks are notorious for going bad and not being serviceable. I feel thankful that I've only had to replace one so far.

 

I'll second Charlie's transmission experience, although happily my Rover shop pegged the alternator and battery right away. Another symptom was that the driver's window would not lift and lower without the lift arms binding. Once the alternator/battery voltage was up to par, all the transmission and window problems went away.

Now I drive with OBD2 voltage as one of the page 1 measurements on my Ultragauge.