2004 Chevrolet Trailblazer Q&A
2004 Chevrolet Trailblazer Question: Why doesnt my truck crank when i turn the key every so often?
poss bad battery cable connection,corrisison or loose - globalhelper
It may not be a bad battery, but globalhelper also said that it could be a loose cable or connection. This could very well be. There was a common problem found from the factory where the positive battery bolt was cross threaded during installation (or this could happen in the field during battery replacement). Disconnect both cables at the battery and check the bolts/threads. There was also a common concern (which we saw a lot of) where the Ignition Switch has been indexed wrong from the factory or during repairs in the field. You asked about the Security System; does the Security message or light come on? Are there codes in the PCM or BCM? Vehicle Cranking is what gets disabled by the Security System. You will need a scanner (not code reader) to find out what codes (if any) are stored, and also to monitor the VTD fuel disable, Crank request signal, and starter relay command signal when the problem is happening. Give me more info. - ChevyASE