Hadn't driven my truck for about 5 or so days. Plugged it in yesterday. Fired it up today and let it warm while I dug it out (had about 8" of snow and ice on it).
Truck warmed up fine. Headed down the road. About 5 miles into the ride, my "Check Gauge" light came on. A quick scan and my volt meter was steadily dropping to nil. Turned around and headed home as I shut everything unnecessary off. In the driveway, I shut it off. A second later, I started it back up and the voltage gauge came up to about 8 and hovered there. Shut it down and left it for half an hour. Came back out and fired it up, went up to about 14. Checked the voltage on my batteries while the engine was at idle and it read in the high 13s.... Belt seems fine. Everything was dry and looked ok from the outside.

Whats next??

 

morning update. After doing a DTR search I checked a few other things and everything seems fine. Truck remained plugged in all night. The volt meter read between 8 and 14. Within a few minutes of driving the volt meter was up and strong on 14. Never dipped. Drove about 30 miles. Included stops and starts. Every time, volt meter started between 8 and 14 and ended up hovering at 14. I ran accessories and haven't had a problem.
Grid heaters didn't seem to cycle much (perhaps since the truck was plugged in?) Anyhow, I'm on my way out for the day. Will report back,.

 

The grid heaters will pull alot of power from a cold start. When mine is plugged in I don't notice the headlights dimming more than twice (this is how I know the grid heaters are working w/o looking at the gauge) but its getting lighter ealier around here. I still plug it in every night to ease start ups. P 1682 is "charging system voltage too low". This may have been from 5 day cold batteries. I would have them load checked. They may be on their way out.

 

I'd guess the grid heater also. My 98.5 dodge wil hover on the low side until I get to around 20mph then the guage show a normal charging state.

 

Truck ran 100% all day yesterday. Did not get plugged in last night. Had to cycle twice before starting. Gauge came right up after starting and no issue. Weather hasn't been REALLY cold tho.

I've started the truck in bitter cold and had the grid heaters cycle and cycle and cycle and never had the volt meter go to zero like that. Could be relays not shutting the heaters off??

 

Relays could be possibly bad but I'd get the batteries load tested, if they are the stockers you are about due for replacements. I think Napa will do this for free. Throwing the check engine light is what makes me think this. If they discharged that much in 5 days they may be on their way out. Kurt

 

Thanks Kurt. Will have the batts checked soon. I've owned the truck since late '04 so it's likely that they ARE original. Optima red tops??

 

When my 01 did that it was the alternator,it would work,then not,then work again,I got some brushes and installed em',works great now.(about $10)
The man at the electrical parts/repair told me it would not work,but about 30mins and it was good to go.