I think driving to a parts store and having them test it was probably good advice at one time, but I’ve heard a lot of stories about the people who are doing the tests that don’t really know what they are doing.

 

I just purchased a voltmeter , and am currently waiting until wednesday to receive it .

 

I picked up a battery tester during cyber week on AMZN for under 20 bucks. ANCEL BA101. Also will check alternator/charging status. I had an issue with my old V12 Jag and this thing flagged the alternator (which was only a yr old). Quick diagnosis because I thought the battery was done. Saves a trip to one of the box stores and the hassle of taking off parts. Cheap tool for the toolbox because you never know when you'll need it.

 

So here are my results from this evenings readings .......Battery is holding at 13 . And with engine running , we're looking at 14.30 . Lights and fan on ....14.30 . Everything seems normal .

 

@Tomzsix Check your battery with the engine off 1st thing in the morning engine off, it will always be about 13 or so until settles after charging. Should be around 12.6

Next I don't think you ever told us why you were suspicious of the alternator

 

Here is the story ; My son , one night after work , started the rover up , and the m and s lights were rapidly blinking , along with the red light on the shifter blinking . He turned off and restarted , but could only go in reverse with low power and lights . I get to his work , and it starts up with no problem , and I get home . I decided that the alternator was not charging enough to cause low voltage for the lights blinking . It was kinda spotty anyway . So I had my shop replace alternator . And have had great success . So then last Saturday , out of nowwhere , it pulls the same stunt on me . Low voltage , but this time , no blinking lights . I drive around and pull into Taco Bell , and all hell breaks loose . Blinking , and low performance , I get home , barely , and try to restart after turning off . Then it woiuld not start . Jumped it the next day , and has been good ever since .No check engine light or nothing . Thats my story

 

feels like loose cable or bad connection somewhere to me. A bad alt would be more consistent in my experience.

 

If the brushes were close to end of life it could be intermittent, but your truck doesn't have enough miles on it for me to suspect that. Original alternator?

 

@Extinct he changed out the alternator.

@Tomzsix That sounds alot like a bad ground or or failing electrical connection. And those are fun to find, but start simple you have a multi meter now so positive to the battery, then negative the each ground point in the engine bay you can reach. The voltage should be the same, as you check each connection inspect for damage and corrosion.
Also check you engine bay fuse box, make sure all the fuses and relays are tight. There are a couple of big connectors in the fuse box too, if you want to check those completely disconnect your battery first, before you loosen or tighten them up.

 

This mornings read is.....12.7
No drain