I have searched this forum and can not find the answer to my question, that I am about to ask.

I recently replaced the TCCM on my 1999 Blazer and I got the updated version 12577412. The 2WD HI button does nto stay lit, and it only came on once, right after I hooked up TCCM. The Auto 4WD has never lit up and the 4WD lo and 4WD HI buttons only light up everyonce in awhile. Everything engages whether the switch lights up or not, so 4WD works, just not the lights....all the time.

I understood that by getting the updated TCCM, it would fix this problem. I did have some corrosion in the plugs, from the old TCCM and tried to clean it up, could that be the problem and I need to clean the connection better? If so, any suggestions as to what cleaner to use to get it done?

 

I have the same problem actually... when I press the 2WD button it will light up again, but I'm not sure what the problem is