Okay guys...new alternator came in, installed and batteries hooked back up. Both batteries were in the 14+ range at the time of hookup, according to my digital VOM.

Pickup started, although somewhat reluctantly. Left running for 10-15 and decided to check voltage at the batteries...both were indicating just over 20 volts at the posts. ????

Preheating the grill for dinner, so I killed the rig. Decided to check voltage at posts while not running...18+ volts now for each battery.

Maybe it's been too long a day, my blood sugar is low or something...but I'm stumped.

Anybody?

 

do you have another meter you can test with?
the numbers you are getting don't seem right

 

That's what I was thinking Ray. I do have another VOM, but it appears the battery is kaput in it, so I'll have to wait to check again.

Went back out a few minutes ago, opened door and the interior lights were dim...not almost out, but certainly dim enough that I noticed. The first time I tried to start after GP's went off, it reluctantly turned over...not real slow, but not like normal...but didn't start. Cycled GP's again and was thinking it probably wouldn't turn over at all, but it did and it started. Instrument panel voltmeter was reading right at the 14-15v area...so I am guessing my VOM is off.

So now I'm wondering...are my batteries almost toast? I'm affeared that the probably are.

 

would be a good idea to have batteries load tested

 

Are you measuring across the terminals or to the chassis ground? Almost (but not quite) sounds like measuring a series connection instead of the parallel. Possible connection from battery negative to ground missing or bad meter.

 

It's the split second spike that happens when you disconnect the battery until the regulator does it's job.

Austin

 

You have the same problem on a boat motor set up with two batteries.. They say never turn the battery switch to off position when switching between batteries..while the engine is engine is running.

 

Well, now I would be scratching my head too.
Suggest checking every connection at the other end of each cable. Possibly a loose ground or something that the alternator is trying to compensate for.

 

...and here's the rest of the story...as it were, the 9v battery in my VOM was toast.

I decided to check the VOM using the voltage out of my shop light, which measured at 156v...a bit high, I thought. So I pulled the back and checked the 9v battery using the old tongue-meter...nary a ting, nothing. Put in a new battery and checked the voltage on both batteries while the pickup was running...14.4 or so volts. So, when I had checked my batteries early today and they indicated 12+ volts, they were no doubt lower, which is why it took 3 attempts to start. Also, it meant that when I was checking the batteries after having driven before and they were at 18+ volts...they weren't...nor were they at 20+ volts when the old alternator was charging them.

Well, called around to get battery prices...and still wound up going to Autozone to get the 850CCA batteries with the 8yr warranty and Free replacement (if one goes bad, they replace both) for 3yr.

Net result...new alternator compliments of the Lifetime Warranty, and 2 new batteries. My wife made the comment while we were on our way to dinner this evening that the lights in the cab hadn't looked as bright in a long time.

Thanx for all for your suggestions. Have a great weekend.

 

Enjoy your weekend yourself Tom. I'm glad that you got it fixed!

 

Thanks for the update and the information on the DMM batteries. Never gave much thought to a weak battery in the meter causing false readings. Guess I need file that away, maybe why I had so much trouble tracing down wires for my campershell wiring.

 

You learn a new thing every day.
Thank you for the update.

 

I had a feeling your meter was giving you problems

 

Glad to see I'm not the only one still using the tongue meter. Thanks for the tip on checking the DMM. Next time I see a funny reading, I'll go check a wall outlet to see if that reading is off too.