On the way home yesterday with my 2000 and I hear the 'bing bing', look at the dash and the check gauges light is on, look around and my voltmeter in the dash is reading like 8 volts, how is this possible I ask myself. I pulled off the hiway into a scenic overlook that has a nice hill coming down in case I need to roll start it.

Did the key on-off-on-off-on trick and it spits out P1684 and P1693, battery voltage low(surprised? I wasn't) and companion code in the JTEC module. Got home it was above 14 volts on the meter and everything seemed normal.

Got the smarty out and pull the codes, P1684 didn't show up, but it shows up in the odometer. Cleared it and see if it comes back. I'm at a loss here, is my alternator going out again? PCM?

Anyone have a similar problem/behavior?

Thanks.

 

sounds like a bad alternator or a bad connection. don't let it stay over 14volts too long or you will be replacing the batteries also.

 

Here's alittle update.
Got home tonight and the voltmeter on the dash was reading 8 volts again. Got the digital voltmeter out and checked the voltage, 14.3VDC.
I'm thinking bad connection somewhere, but where would be the best place to start?

 

Any chance it is just the grid heater cycling on and off? I'm sure you know how that will bring the voltage down and cause the check gauges light to come on.

 

Doubt it, I've reading 14.3 volts when the computer and the dash gauge are thinking there is much less, like there's no connection at all.

 

Update:
Problem found monday morning, Alternator was on its way out, rectifier was bad.