Gauges not working on 03

Battery went dead on the 2003 (my fault) and rather than jumping it and stress the alternator, I hooked up a battery charger and let it slow charge.
When the charger said it was happy, I tried to start it. turned the key on and saw the gauges dive to way below their low settings then rise up to the low point. After the glow light went out, I started the truck, normal sounding start. when it was running, the gauges never came up to any value above the bottom end. I know the tank is near full, The voltage should be good as fast as the starter was spinning and so on.

The Tach does work.

I also noticed the ABS light on, the brake light on and the info center said "unknown driver" with a #3 key in it.
The radio was lit up but no sound from the speakers.
I seem to remember this situation on here once upon a time, but I cannot find a post similar to this problem.

Any ideas? Where to look?

Thanks in advance for any help

Mark

Quote:

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Originally Posted by markelectric

Battery went dead on the 2003 (my fault) and rather than jumping it and stress the alternator, I hooked up a battery charger and let it slow charge.
When the charger said it was happy, I tried to start it. turned the key on and saw the gauges dive to way below their low settings then rise up to the low point. After the glow light went out, I started the truck, normal sounding start. when it was running, the gauges never came up to any value above the bottom end. I know the tank is near full, The voltage should be good as fast as the starter was spinning and so on.
I also noticed the ABS light on, the brake light on and the info center said "unknown driver" with a #3 key in it.
The radio was lit up but no sound from the speakers.
I seem to remember this situation on here once upon a time, but I cannot find a post similar to this problem.

Any ideas? Where to look?

Thanks in advance for any help

Mark

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In all likelihood, you have at least one bad battery. A fast-spinning starter does not indicate the "health" of the batteries, one or both. One bad battery can allow the pair to charge, but the voltage will quickly fall to below optimal/allowable. This will play havoc on the entire system, especially the 2003+ models. Disconnect them and charge to full, independently. Once fully charged, check their independent voltage after at least 6 hours (disconnected, doing nothing). They should be at least 13V (13.6 nominal), and should be within .5V of each other, while losing no more than .2V from full charge and the 6 hours. While they are disconnected, check and clean all connections, and ground the Batt+ cables to the chassis (batteries still completely disconnected, at least 30 minutes to an hour, this will default the computers, including the BCM/IPC).

If battery(ies) fail, replace the pair (unless the good battery is relatively new and checks perfect). If they check out, install them and complete 4-5 key cycles (without starting), about 2 minutes each, on/off (this will expedite all the diagnostic cycles and reinitialize the systems).

DM has offered some good advice...

Just thinking out loud (so to speak).

With dead batteries and even with the key off, connecting a battery charger allows whatever the charger is putting out to reach the ECM and other electronic modules. Any arcing, voltage/current spikes or voltage variations produced by connecting a battery charger could affect the electronic modules, which are always drawing a small amount of current even with the key off.

Maybe we should charge dead batteries only after disconnecting the negative battery cable from each battery.

That being said, we really haven't heard any horror stories about damaged ECMs when charging batteries... Could be there's more protection built into the modules than we know.