4x4 wont engage, shift light flashing

All_talk · February 15, 2004

Hi Guys

Looks like a great forum.

My suburban wont go into 4WD, LO or HI, light just flashes forever, where should I look first? I can feel the transfer case shifting into LO and sometimes it thunks a bit, related?

1997 Suburban 1500, 5.7 Vortec

Thanks

Gary

Shaners · February 16, 2004

I'm guessing that on your '97 it would be the thermal actuators.

On the new body style trucks it would most likely be the switch...

BTW!!! Welcome aboard!!!

Rookie · February 16, 2004

Hope it nothing expensive. Get used to the clunk i think we all have them. Welcome we all have a lot of good info but please make your own choice when it come to fixing your truck.

All_talk · February 16, 2004

Shaners, thanks for the info and welcome

The thermo actuator was just replaced with the newer electric motor type and wiring harness by the used car lot mechanic, I’m not to confident in his abilities. So I did some checking in the shop yesterday, new actuator is making noise but not moving, I checked it out of the axel and the pin doesn’t extend. The conversion requires a wire to be tapped at the top of the transfer case, I’m wondering if the new actuator is bad or maybe he tapped the wrong wire. From what I’ve read online the proper wire is “light blue” he tapped an orange one? There is a TSB about this #764301 but I don’t have it. Anybody know the right wire for a ’97 Sub?

Gary