I'm currently working through trouble shooting what I now believe to be an electrical problem with the 4WD in my 2002 Mazda B3000. Currently, the 4WD is not engaging when I use the dash switch. So far, here are the things I have done to try and troubleshoot the problem: 1. No blown fuses in either the engine fusebox or the cab fusebox. 2. Replaced the 4WD computer module in the passenger side kick panel and have made sure to disconnect the battery and drive it after to ensure proper calibration. 3. Replaced the transfer case motor actuator. 4. Replaced the 4WD dash switch.

When the ignition is on and I try to switch between 2WD and 4H and 4L, I can hear the transfer case actuator try to engage into 4H, but then revert back to the original position of 2WD. When I start the truck, the 4WD dash lights flash once and the disappear. Additionally, the computer module can be heard clicking about 4 times. So, I know that I have power going to the transfer case motor, I know the computer module is receiving a signal from the dash switch and I know the dash light bulbs aren't burnt out because they do flash. The final test I did was to remove the transfer case motor actuator and manually engage the 4WD. When I did this, the 4WD in both 4H and 4L were engaged, but no light on the dash came on. I"M STUMPED!!! Any ideas for what I'm doing wrong or what this could be?

I'm fairly certain at this point it's an electrical problem, but I don't know anything about electrical or how to trouble shoot. Any advice would be welcomed and greatly appreciated!

 

Can you remove the shift motor from the transfer case and rotate the shift shaft manually? It could be a mechanical issue internal to the transfer case.

 

Yes, I was able to manually rotate the shaft inside the transfer case and drove it in 4WD. I finally was able to track down the problem, and it was electrical. The 4x4 CM was sending signal to actuator to engage 4wd, but the 4x4CM was not receiving a signal back that the 4wd was engaged. Had to solder a wire in order to get the 4wd working again. THank you everyone for the help!

 

Good find. Thanks for letting us know what the solution was. So many people have issues and get them fixed that don't report back. At least if someone else has this same issue they will hopefully find this thread.