2001 B4000 4x4 quit working

[griffse]

I have a 2001 Mazda B4000 and the four wheel drive has stopped working. When I turn the electronic control to 4x4 high, nothing happens. No noise, no clicking nothing. Same for 4x4 low. I recently had the truck at Sears to have the tires rotated and aligned, I took it back and they said nothing they did could have caused this. Browsing the forum I see some differing opinions on that. Any help would be greatly appreciated.

[PrairieSparky]

I would suggest to follow the wiring harness back as best as you can and check for any loose connections. If it does nothing it sounds like a bad connection. I don't know much about electronic 4x4 but would guess that there is a relay or control module somewhere and maybe check a junkyard for one. Or use an voltmeter to check power along the way using a wiring diagram, which can be found in repair manuals, to check voltage path and how many volts should be where. Just my thoughts, let me know.

[griffse]

Thanks, I 'll check tonight I appreciate the help and will post the results.

[griffse]

I can't see anything loose anywhere, I don't know where the wiring harness for that particular mechanism is.

[PrairieSparky]

I think it maybe time to invest in a chiltons book

[muddy-SA]

The rfw controll box is under the left front scuff plate. I doubt if there is anything there you can check. Open the bonnet and find the brake Booster. On the booster there are 2 vacuum actuators. Follow the pipes to the diff in front and check if they are connected. The RFW control box sends a signal to the From the switch to the acutators and onlyu when the front diff is engaged will it shift to 4H or 4L.

[griffse]

Thaks for the reply, here is an update. The 4WD PCM is lodated on the passenger side behind the kickpanel. I checked those connection and they look fine. When I rotate the Knob on the dash that module no longer makes the little click it used to. That would make me think the problem is before it reaches that module. I also noticed the light bulb behind my tachometer has burned out or shorted, possible culprit? It's going to a guy from my chruch tomorrow so hopefully he can help me out while he replaces the front brakes. I still suspect that getting my tires rotated at Sears was not helpful.

Originally Posted by muddy-SA

The rfw controll box is under the left front scuff plate. I doubt if there is anything there you can check. Open the bonnet and find the brake Booster. On the booster there are 2 vacuum actuators. Follow the pipes to the diff in front and check if they are connected. The RFW control box sends a signal to the From the switch to the acutators and onlyu when the front diff is engaged will it shift to 4H or 4L.

[griffse]

Hey does anyone know where I can download a repair manual or wiring diagram for a 2001 Mazda B4000?

[griffse]

I have taken the truck to two local mechanics, neither was able to diagnose or solve the problem. It goes in to the dealer next Wednesday, hopefully I will be able to post a solution at the end of all of this.

[Kyrasis6]

I have a factory manual for the 96 but just the section on the transfer case will probably take me 3 hours to scan.

[griffse]

Here's a load of crap, the dealer said both the Control Unit, and the Change motor are shot. To replace both is $651, and they have to order the parts. What a load, how can you tell if both are shot if you don't replace one at a time? If the contorl unit is broken, how can you test the change motor? This sucks.

[archer of loaf]

i know this won't help, but the 4x4 is a constant problem in the ford/mazda b4000 (same truck) where i work. many of them will no longer work. the mechanics suggest just get rid of them.

[griffse]

I am definitely not getting rid of the 4X4, I use it. This guy said he has never seen this happen either which I find hard to believe reading this forum. Does anyone know where I can get the 4X4 control unit where it won't cost $150?

[Kyrasis6]

Almost all testing in the factory manual requires a ford scanner to perform the tests. About the only thing you can test for is shorts and opens by backprobing with a dmm.

[TWCAMC]

I recently purchase a 2001 Mazda B4000 and realized that the 4X4 quit working. It has the same symptoms as those suggested in this posting: no clicking sounds, no light on dashboard, nothing. Any help besides those listed here will help. Thanks