Hello everyone!
I have a 2000 Chevy Blazer that I bought from a guy that has a few issues. I don't know if they are related but he said he had the windshield replaced by a local window company and says the issues all started after this happened. He also said that the issues would only happen when the vehicle got wet at first(car wash or raining) but now it is all the time. Firstly the transmission slips 3rd gear and only 3rd gear, 1st and 2nd work fine and as intended but it will not go into 3rd gear. Aside from that the only other major issue is the instrument cluster will go haywire sometimes, all the gauges will stop working and all the dash lights come on. I have disassembled the dash and inspected as much of the dash harness, connectors, and fuses as I can to find no issues. I have a couple ideas but just wanted to hear what some people that are well versed in the chevy blazer have to think about it or some ideas on what to test or check. I know the BCM could be cause both issues but I wonder if just the cluster and the tranny decided to **** out about the same time. Has anyone seen this before or have any ideas on what direction to go?

 

I would first find out where the water is coming in, as if you fix the problem and water continues to get in, might be a wasted job. Transmission is an issue I'm not familiar with, but someone will chime in

 

When I disassembled the dash and for the time I have had it I couldn't find anywhere that water was or had gotten into the cab(not to say it never has) but the previous owner also said the glass company replaced the windshield a second time after the initial issues. At this point in think what I am thinking is to replace the cluster and rebuild the transmission and go from there, I just wanted to see if anyone had any ideas on anything else to look into or if someone had come across something similar before that might be able to give a little insight.

 

If the 3/4 clutch pack has gone, when the transmission tries to up-shift into third, the engine will rev higher and you will lose drive to the rear wheels.

 

This is exactly what it does when shifting into 3rd, I just didn't know if something else could be causing both issues like the ignition switch, cluster board, a harness, or something else. but the fact that the transmission issue is consistent but the cluster isn't makes me think they are unrelated and just started happening around the same time.

 

The loss of the 3/4 clutch pack is not an uncommon issue for Blazers of our vintage. I managed to ruin mine not by lack of maintenance but rather by towing my boat when I had it in Overdrive. That was an expensive mistake!

Good luck with the rest of the repairs. Hopefully the electrical stuff will be easy enough to fix.

 

Thank you Christine, I know the BCM can cause issues but the fact that NOTHING else, except the AC which is because the cabin air sensor is shot, is doing anything it shouldn't leads me to believe the issues are not connected I think I will start with replacing the cluster and see from there. My understanding is the heat/ac system works off cabin air temp so with the sensor not reading it defaults to like -30 or -40 degrees Fahrenheit so it tries to warm the cabin up to 60 or 70 degrees instead of cooling. That is the only other issue I have with the vehicle.