Hello, please forgive the long post. I am new to the forum here and and trying to put an end to some intermittent starting and transmission shifting issues.

Working on a 97 S Blazer, now with around 155,000 miles. There have been starting issues off and on for most of the time I have owned the vehicle (9 years). At first, when you would turn the key, the guage lights would come on and then when attempting to start, nothing would happen. I would just have to continue to cycle the key until it finally cranked and started. I replaced the ignition switch in 2007 (with a Echlin brand switch from NAPA). The problem seemed to pretty much go away, but not entirely as there were, at times, instances of having to cycle the key to get it started.

About 3 years later, the transmission started shifting real hard and the SES light came on. The repair shop pulled several codes, P0740, P0753, P0758, P0785 and P1860. They diagnosed the problem as the ignition switch and replaced it with a Delco unit.

Since that time, again there have been intermittent issues with starting, though never stranded, it has been a real pain.

The latest issue came a few days ago, when it just seemed to be real underpowered. The SES light came on and then I couldn't remove the ignition key. The next day, with a scanning tool, I pulled several codes (P0740,P0753,P0758 and P1860). When reading about those codes, it became clear that it was under powered due to starting off in 3rd gear. Since that time, it has started fine, driven and shifted fine, and I have been able to remove the key, though I don't know for how long.

The transmission has been fine, other then the 2 instances mentioned, so I don't think there is a real issue with the transmission.

As I really don't want to look at replacing the ignition switch again (3rd time in 6 years?) I need to know if I am treating a symptom of a different problem?

Weeks or months may go by before it will act up and the key will need to be cycled many times before starting. If I have the time to troubleshoot, it has started fine.

So, is this "common" behavior for the 97? Have I just had bad luck with the 2 switches I have purchased previously, or do I need to look for another component that is the real problem or that is causing the switches to go bad?

Thoughts and suggestions?

 

Haven't had any issues for the last couple of weeks, but sure that something will come up at some point.

Anyone have any thoughts to share?