I have a 99 silverado 4.8 auto. I started it this morning and the battery light stayed on and the odometer isnt there, also no ac. I drove it to work, it ran and drove fine but no ac and battery light is on still. It sat all day and when leaving work 8 hrs later it was still on, so I slammed the door and the battery light went off, the odometer lit up and the air came back on. I drove 20 miles home with no issues, let it set for an hour and started it back up and the battery light is back on, no odometer and no ac. I have googled, and searched for hours to see if this has happened before but cant find anything. So far ive cleaned body grounds and checked all fuses. Ive had a couple people tell me the cluster is bad, but would this affect the ac also? Any advice is appreciated.

 

When you say no ac, what exactly do you mean. It just doesn't blow cold air, or it doesn't blow any air? Did you disconnect the battery for a min or so?

 

when the battery light decides to come on, the ac will quit working. The ac system is fine (blows Ice cold). the fan will stop blowing. Also noticed the temp gauge and gas gauge arent working either. the mileage display will come on on the first click of the key, but dissappear when the truck starts. Yes i have unhooked the battery for about 15 mins but still no luck.

 

When all this stuff happens, are you getting voltage to the fuse block inside the cab?

 

How old is the alternator?

 

When the battery light comes on the truck is telling you there is a voltage issue... This could be a dead cell in the battery not allowing it to charge properly, a bad alternator not putting out enough voltage or any voltage, it could be a loose or broken wire, and last but not least corrosion.

I believe there is also a fuse but most likely you would have no power if that was blown.

As far as the AC not working the computer realizes there is a voltage issue and shuts down non essential things like the AC, it could also be shutting down your cluster as well.

I would get a meter when the battery light comes on and see what the Voltage reads with the engine running. If it reads low its in the charging system. If the voltage is fine then you could have an issue with the cluster, The main wiring harness, The ECU, or possibly the BCM.

 

Also if you have a code reader see if there are any codes present. some voltage codes will not set a check engine light but will show up if you check for codes.

 

The alternator is 1 year old. No codes showed on reader. Also 4 days ago i took the truck through some pretty rough trail riding and mud, could this possibly have rattled something loose in the cluster? I never had any issues before this,but it didnt start happening till 3 days after the trail ride. Ive checked all the grounds underneath the truck that are visible and they all seemed to be clean and tight. Im gonna try to swap clusters with a buddy today. Also i checked the voltage at the battery with the truck running and the battery light on and had 14.2v

 

SOLVED!!!! it was the ignition switch in the column. Thanks for the advice guys.

 

Good to here. How did you find that it was the ignition switch???