One problem related to battery has been reported for the 2003 Chevrolet Blazer. The most recently reported issues are listed below.
1. Speedometer acting erratically. 2. Dealer wanted to charge $450 dollars to change speed sensor. I told him he was crazy. They reconnected. Speedometer stared working again. 3. 7 months later speedometer starts acting erratically. I search websites and find that many other owners of 2003 tahoes experience the same thing. Ordered new speed sensor to for self installation. Yet to install. 4. Speedometer starts working again after battery changed. 5. Runs for 5 days working fine then act erratic again. 6. Ready to change. 7. Thought I'd complain first. Think this is a safety issue and something should be done about it.