I have changed everything electrically, now the 4hi light blinks and nothing happens. Its a 4 button dash switch. If I push the 2hi or 4low I get the service 4x4 light. If I turn the ignition off the service light resets?

 

Welcome 2 the Blazer Forum... I am not familiar with the 4 button dash setup, my 98 has the 3 button switch on the dash... Have no doubt, someone else will be able 2 help you figure it out

 

Please describe exactly what you have done so far, why you did it, and what has been replaced - did you get used parts or new parts? Where did you get them? Then we can begin to help. The blinking light by itself means nothing specific other than it is not completing a shift.

 

I have changed the incoder motor (new) rockauto also changed the TCCM (new) and the dash switch (new) both from Orieliey.
The TCCM and dash switch made the most difference as the service 4x4 light went out and I can hear relays but doesn't sound like it's trying a gear change.
also the light is blinking without pushing anything, the TC is in neutral.

 

By 4 button you mean the dash switch has the auto button, correct?

If so - check 4 fuses. 2 in IP fusebox (#12 and #15) and 2 in underhood fusebox (ATC 20A and Crank 10A).

If OK check for corrosion on TCCM connectors especially for the the heavy red and black wires- repair if corrosion found.

If OK make sure both plugs for the encoder motor are connected and that the terminals are good and not corroded.

Was the TCCM one that is specific for the vehicle like a Cardone, or was it a GM TCCM? Some are universal models that need programming.

Did you try to run the encoder motor by plugging into the system before installing it on the transfer case? This can ruin it.

If you remove the encoder motor, can you rotate the shaft of the transfer case through the different ranges and gears with a wrench?

Do this stuff and answer questions and If not fixed we will continue.

Here's a link with some helpful info.

https://blazerforum.com/forum/tech-a...rmation-41198/