Battery / Alternator issues....

[Scot]

I already ordered new everything. Here's the story anyway. My batteries have been dead in the AM a few times recently. Not having to work today I put them on a slow charge all day.

After the charger said "full" I checked the voltage and found the following.

No load, nothing on voltage was 15.5 (Not exactly what I was expecting.)

Key on, glow plugs running voltage was 14.8

Truck running, glow plugs on was 14.2

After glow plug shut down I jumped to 18 VOLTS. (NOT what I was expecting)

I was expecting the problem was low voltage, but it appears high can be a problem too?? So a large case 140a alternator is on the way. Luckily shipped from my own state and won't take long.

 

[Tbar]

Check it again using a different multimeter.......


Tbar

 

[Scot]

Thanks,

That was the first thing I did. My 2 digitals and a friends old school meter all had similar results. I've had trouble keeping batteries in this truck since new. Maybe this was my problem all along. I was just lucky enough to catch it in the act this time. Every other time I've tested it the voltage was within range.