i sent my 03 silverado 6cyl. in to dealer for a recall/service bulliten for a faulty hvac bolwer control. they fixed it ,said the old one had in fact melted.
since i got it back my dash said my coolant level was low. i checked & it was fine. the next week it said my oil level was low. again i checked . it was good.
yesterday i went to go to work and it acted like the battery was dead. did not start. if i turn on my fog lights (aftermarket wired directly to battery) my speedo and tach twitch. any ideas would be welcome.

 

They may have disconnected the battery when the did the servicing and did not get in on tight, check the grounding cable from the battery...

 

tried battery terminals. they were tight.

 

Take it backto dealer and let them figure it out.

 

I agree with Old Wrench..... dealer was the last one under the hood, take it back to them... OR... when you oil light comes one for low oil... call the dealer ASAP.. and tell them it never did that and you refuse to drive it back to the dealer in fear u might blow the engine.... that will get there attention...