Automatic Four Wheel Drive Control Module

[AledoGYoung]

Has anybody replaced the automatic four wheel drive control module in their bronco ii?

 

[wildbill23c]

I'm sure a few people on here have. What's the question pertaining to replacing one?

 

[RonD]

I never have, I also haven't seen anything on here recently about a bad one.

Have a look here
http://www.therangerstation.com/tech_library/EDiagrams/index.htm

Look at the two Shift Control diagrams.
Looks like there are two fuses
And it has the "pin out" numbers and wire color for trouble shooting.

 

[AledoGYoung]

Well I cleaned up my shift motor due to the fact that it would not go into four wheel drive or the 4 high indicator light would not come on, but after cleaning it would go into 4 high and 4 low just fine but the 4 high light will not come on (4 low light does come on when in 4 low). Now I can hear the shift motor go into each but the control module keeps clicking and it goes back into 2 wheel drive. It is like it is not getting the signal that it is in four wheel drive. I don't know what else to check besides the control module in the dash. Any info will help. Thanks

 

[adsm08]

I have not replaced one, but I did take mine and throw it away.

Also, good luck finding your 4x4 module if you are looking in the dash. The module is behind the little panel behind the driver's seat.

 

[AledoGYoung]

The 4x4 control module is in the dash right next to the right front speaker in a bronco ii. I have found it. Does anybody know how reliable the test for it is?

 

[4x4junkie]

1988 = module in dash (1989/1990 = in panel behind seat)


With just the pigtail connector connected (other two disconnected), you should get a click, and several flashes of the red LED light (four I think) if the module self-tests OK. If it lights up solid, then test failed (that, or you didn't unhook the proper connectors).

Dunno how reliable the test is, but as said, failed controllers are very rare (49 out of 50 times it's the shift motor or it's sensor, or the little stopper bushing around the screw on the internal gear has disintegrated).

 

[adsm08]

1988 = module in dash (1989/1990 = in panel behind seat)

Then what did I pull out from behind that panel that had "4x4" printed on the sticker?

 

[4x4junkie]

On a 1986-1988 truck? Did it have the overhead control buttons? or were they on the dash?

 

[adsm08]

Over head console buttons. I know there is a relay pack in the dash, because you could hear it clicking when you hit a button, but that didn't shut up until I pulled that other module out.

 

[4x4junkie]

I'll bet $$$ what you were hearing click was the 4x4 module itself.
It's a black plastic box about 4x6x1½ inches if memory serves right, has several relays in it, small aluminum finned heat sink on one end, and has a little plastic lever button thingy on the side with a red LED. There are two separate plugs that plug onto one end of it, the other end of the module has a pigtail connector coming off it.
It directly controls the shift motor on the transfer case.

Not sure what you pulled out of the panel on yours, but if it shut it up, I guess that's all that really matters.

 

[ronclark]

1988 = module in dash (1989/1990 = in panel behind seat)


With just the pigtail connector connected (other two disconnected), you should get a click, and several flashes of the red LED light (four I think) if the module self-tests OK. If it lights up solid, then test failed (that, or you didn't unhook the proper connectors).

Dunno how reliable the test is, but as said, failed controllers are very rare (49 out of 50 times it's the shift motor or it's sensor, or the little stopper bushing around the screw on the internal gear has disintegrated).

My moms 88 BII had a bad controller, throw us for a loop too because the self tested ok, but after hours of testing everything, cleaned the shifter motor and the brushes. ended up getting a yard controller and everything worked.
Thy sure can but lots of fun troubleshoot.

Cleaning the transfer case motor

Transfercase troubleshooting

 

[AledoGYoung]

I already cleaned up the shift motor and replaced the bushing inside of it also. The shift motor goes into the right gear but it is like the control module is not getting a response that it went into to 4x4 so it takes it back out into 2 wheel. While this is happening the control module clicks until it goes back into 2 wheel. I did the control test and I got a constant red light?? Does that mean it needs to be relaxed? Where is the shift motor sensor?

 

[4x4junkie]

I did the control test and I got a constant red light??

You unplugged the two connectors on the end? (leaving just the pigtail connected) If so, then yes, that's a fail.

Sensor is inside the shift motor itself (it's that circular disc on the gear with the wiper contacts against it).

My moms 88 BII had a bad controller, throw us for a loop too because the self tested ok, but after hours of testing everything, cleaned the shifter motor and the brushes. ended up getting a yard controller and everything worked.
Thy sure can but lots of fun troubleshoot.

Cleaning the transfer case motor

Transfercase troubleshooting

There's always that one in 50... Looks like you got to be it lol.
Fortunately the OP's seems to have failed it's self-test so that at least makes it a lot easier.

 

[AledoGYoung]

Yes, I unplugged the two connectors and left the pigtail connected and got the solid red light. So I am guessing that I need to replace the control module? Also, Is there any way to test the sensor? When I cleaned the shift motor I made sure that circular disc was clean.

 

[ronclark]

There's always that one in 50... Looks like you got to be it lol.
Fortunately the OP's seems to have failed it's self-test so that at least makes it a lot easier.

I always seem to get the strange problems to solve. There is always the 1% failure.

 

[AledoGYoung]

I guess I am a part of that small percent too because I have checked everything and the control module is the only thing doesn't check out. So hopefully I can find a control module at a salvage yard and I can plug it into my bronco ii and see if it works before I buy it.

 

[KCB2]

I would suggest pitching the push button. I have a guy here in Kansas City that builds a conversion kit for these to eleminate the probalematic push button crap. If you would like more info on it pm me and i can get you his contact info.

 

[AledoGYoung]

What other vehicles can I get the same 4x4 control module from?

 

[AledoGYoung]

I have heard that explorer up to 1994 will work?