Hello all Hopefully someone can give me some advice. Over the weekend I was in the mountain checking out the hunting spot. While I was up there I wanted to run it in 4wd for a while to make sure everything was working good for the upcoming winter season. Well that didn't happen. I locked the hubs put it in drive and started driving, flipped the switch to 4hi and nothing! I could hear the relay in there going crazy clicking on and off but it didn't engage. Both 4hi and 4low lights started blinking. So I switched back to 2wd and tore off down the dirt road. The rest of the day both 4hi and 4low lights blinked about 6 times every couple minutes.

I had this problem one other time only that time I wanted to disengage 4hi and it wouldn't. When I flipped it to 2wd the 4hi light stayed on for a minute then 4hi and 4low both started flashing and it stayed in 4hi till the next day then when I drove it again it was back in 2wd.

Also one day during the summer I noticed the lights started blinking while I was driving.

 

I guess if it was me I would check for a blown fuse first. If fuses are good check the wiring harness and connector underneath at the transfer case, unplug the connector and look for corroded or oxidized contacts, also look for abraded or rotted wires in the harness. Have someone work the switch for 4H and 4L and watch and listen to the motor to see if the shift motor tries to run in either direction. If you have wiring diagrams or motor pinout you could pull the motor and bench test it to see if it runs with direct connect to 12V.

When my 4x4 stopped working a few years ago it was the 4x4 control module.

 

Ok thanks for the info