'01 Sport Trac 4x4 Issues (Will not turn on)

[grzy]

Hello everyone,

First off, I want to say thanks for reading my thread and giving any tips/advice in demand.

Ok...So my problem is my 4 wheel drive decided to stop working on me. So after reading a bunch of other forums, I have tried reconnecting the wire harnesses a couple times to the 4x4 control module, but that as not fixed the problem.

Neither the 4 high or 4 low works. If you switch it to either of these, nothing happens (no clicks/no lights). However, the 4 high and 4 low lights do flash on when starting the car. The wires and connections look good (no corrosion or bent prongs) I also tried some dielectric grease in the connections and still a no go.

How do I determine if it is the control module that is bad, or if it is something else?


Thanks!

P.S. I checked all the fuses and they are fine.

 

[ncranchero]

Do the same for the connections at the shift motor as you did for the module.

No communication with the four-wheel drive (4WD) control module

Possible Sources
Four-wheel drive (4WD) control module.
Central Junction Box (CJB).
CJB fuse 35 (15A).
CJB fuse 10 (7.5A).
Circuitry.

If you can perform basic automotive electrical diagnostic operations just send me an e-mail and I'll send you the diagnostics from the Ford manual.

 

[grzy]

Thanks for your response. I will for sure do the same for the connections at the shift motor.

Thanks,
Mike

 

[grzy]

So, I checked the voltage readings from pins 1 and 2 to the ground, and they both are around 8.1. It says in the diagnostics that if they are under 10 to repair the power supply as necessary.

Do I need to focus on this? Could this be the reason that the 4x4 will not respond? Not enough voltage supply?

Thanks again.

 

[ncranchero]

I'd say yes. Is your battery down that low? Check your fuses for good contact.

F1-13 (704) in the under hood box and F2-35 (931) under dash box feed those circuits.

 

[grzy]

Thanks for the quick response.

The battery is just over 12 volts.

I rechecked the fuses and they seem fine. However, after reseeding fuse 35, I measured the voltage at the module and it only read 1.2 volts. So I went back and reseeded the 35 fuse again and now it reads 8 volts.

Of course I have no 15 fuses to replace it with right now. So I am going to run to the store and get some. Maybe replacing this fuse will cure the issue.

Thanks.

 

[grzy]

Well, no luck with replacing the 15A fuse. I am still getting a reading of 8.2 volts.

Is there any way that the control module is damaged so the correct voltage can not pass through it?

To verify, that I am reading it correctly, the grey junction is a, and the black is b, correct? In order to get the voltage, you leave the black connected and measure from pins 1 to ground and pin 2 to ground...correct?

Thanks and sorry for all the questions, I am new to fixing my own vehicles.

Rookie,
Mike

 

[ncranchero]

The 2001 & 2002 wiring diagrams do not give the connector color but the 2003 does and the 281a is the black connector & the 281b is the gray connector. Wiring between the years is the same so we will assume for '01 & '02 that 281a is black & 281b is gray.

Test the black connector. Pin 1, circuit 931, is an Orange wire. Pin 2, the 704 circuit, is Dark Green/Light Green. You should disconnect the connectors from the module and test the voltage from the connector pins with the negative lead of the meter grounded to the body.

 

[grzy]

OK...This is a stupid question, but how do I test the connectors pins? I can't get the red to touch it. Do I have to take off the red part on the connectors to expose the pins?

 

[ncranchero]

I usually just insert a paper clip if the pin is inaccessible with the test lead probe.

 

[grzy]

Ah, thanks for the tip. I will try this when I get home from work today.

 

[grzy]

Well, after my lapse in measuring, there is enough voltage. It seems everything checks out with the connectors to the 4x4 control module. So all of test B passed.

Now onto test C, but I can not get any codes. So the other things I can check out would be the switch. Where is the MSS located? Is it near the control module? I do see another black and grey harness.

Any tips would be great.

Mike

 

[yipus]

New to Explorer, renting one for the first time; no manual. Pushing 4x4 buttons in neutral; can't get it to turn on. How do I turn 4x4 on?