A few days I needed my 4WD and it worked fine. The next day when I hit the 4WD Hi button, no light and did not engage. I put it in neutral and hit the button and both the 4Hi, 4Lo lights flash for a few seconds and I hear it click like it has engaged. Put it back in drive and nothing. A friend of mine suggested that the 4WD selector switch has gone bad. Is that the problem or something else? The vehicle in question is a 1994 Chevrolet S10 Blazer Tahoe LT with the Vortec V6.

 

The light on the push button flashes 5 times. That is a diagnostic code but I cannot find any one or any place that knows what that code is. I took it to a mechanic in town and he said they tested it and the 4WD was just fine. But it does not light up the green light when I push the 4Hi and it does not make the sound when it normally engages. I put it in Neutral and hit the button, it makes the clicking sound it usually does then the lights on the push button flash 5 times. I have an appointment at the local Chevy service at the dealership and they are going to look at it. When I find out what it is I will come back and post it for all the others who have a 94 and the same problem.

 

Okay. I took my 1994 Chevrolet S10 Blazer Tahoe LT to the Local Chevy Service Department today. It was the Transmission Case Encoder Motor. $142.99 at Advance with a $20 core charge. GM has the part but it is $500 and will take a few days to get there. It cost total to track down the problem and put the new motor on $258.00 So if you are having this problem and it is not your switch, vacuum lines or TCCM then it is the Transfer Case Encoder Motor. Hope this helps someone else that has this problem