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!

 

Is there any clicking sound when you try it?

 

Yes, the computer module clicks several times both when I turn on the car initially and then when I switch between 2WD and 4WD. It sounds like it is trying to engage but then reverts back to the original setting. If that makes sense...

 

Faulty 4WD module or transfer motor.

 

I have replaced both the 4WD computer module and the transfer motor. The transfer motor will attempt to move into the 4H position with the ignition on but will ultimately revert back to 2WD. The computer module clicks when I start the truck and when I try to switch between 4WD and 2WD. Still think the issue is with one of those two? Both of these things are brand new...