1995 Chevy S10 4wd Blazer 4.3L V6 Vortex

4wd is electronic; activated by push-button actuator located on dash. I have replaced this once; a couple years ago; problem solved. Put a new one in this time- didn’t work. When I attempt to go from 2wd to either 4hi or 4lo by putting the vehicle in neutral and pressing 4lo button and returning to park while indicator light is blinking and waiting until indicator light stays lit b4 putting vehicle in gear and attempting to drive. Thing is… both 4hi and 4lo indicators stay lit and vehicle ‘winds out’ and seems to have ‘no power’. Returning to 2wd has to be done the same way. Not sure if the problem is the module, the motor, or is there another vacuum actuator somewhere? Central Illinois has been getting quite a bit of snow and 4wd is critical to getting around. Thanks in advance for any insight on this… 4wdriveless

2 thoughts on “1995 Chevy S10 4wd Blazer 4.3L V6 Vortex”

  1. First thing I would try would be to thaw out the blazer. If you can get it inside a heated garage it may fix it right up. I have seen this many, many times during heavy snow and cold weather. Moisture and rain and snow get into places it isn’t intended to and cause issues.

    Some common problems with these systems are:

    1) Logic lock-up within the transfer case control module. Removing the 4WD fuse for a few minutes may correct this issue (fuse location varies according to the model). Resetting the TCCM may only be a temporary repair. If the system fails again, further diagnoses may be required to isolate the fault.
    2) Faulty encoder motor on the transfer case.

    The Bulb Check
    First Generation

    When the ignition key is cycled from OFF-RUN-START and is released back to the RUN position after the vehicle starts, the 4WD mode lights should illuminate for 1 to 2 seconds and then go out. If they stay on, there is a problem with the 4WD system. Fault code(s) should be stored in the TCCM, which displays stored codes by flashing the mode lights. If one or more of the mode lights do not illuminate during the bulb check, the problem could be a burned out bulb or something more serious requiring proper diagnoses.

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