2001 Ford Ranger 4 Low Problem
 

Hi Ron, lol I know you'll see this so may as well address it to you...ha! Just saw your response on rangerdad01's thread about his xcase motor not shifting.

Anyway, my Ranger won't engage into 4 Low. It'll engage into 4 High and drives and feels like 4 High, but no 4 Low at all. No solenoid shift, no indicator light, no nothing.
Take a shot at helping me figure out my issue? I saw it mentioned the 4x4 selector switch rarely fails.
My thoughts:
-Depressing feet on clutch and brake pedal aren't the problems here
-My shift motor must be fine since I can shift into 4H
-4x4 shift interlocks must be ok since I can shift into 4H
-It's not the indicators since I have nothing from the solenoid (I'm physically not getting a shift) also I do have the indicator for the 4H

So, what do y'all think might be an issue here? Should I go behind the middle dash panel and bypass my switch to see if the switch is the problem? Or should I be targeting my 4x4 control module, and if so how can I test this module?

Or is there something else I'm overlooking?

Attached is the wiring diagram I've been using.

Thanks for the help.

The 4x4CM is behind passenger kick panel in 2001 to 2003 Rangers, it was moved to behind the radio in 2004 because GEM was removed from there and to make room for the SJB behind passenger kick panel

With manual trans you need these 3 things to be true or no shift to 4low
Speedometer working and at 0 MPH, broken speedo disables 4low
Brake pedal sensor showing 12v foot on the pedal, and showing ground when foot is off the pedal(not related to brake lights)
Clutch pedal down showing neither 12v or ground at pin 12 in drawing <<< this clutch pedal switch is missing on your drawing

You may want to pull off the kick panel and pull out the 4x4cm and unplug it, then test the red/light green wire(pin 12) for ground and 12v by pressing brake pedal, and no 12v or ground with clutch pedal depressed
Pin 1 on "upper" connector should have 12v all the time so can be used to test pin 12 for Ground, and pin 2 on "lower" connector is full time ground for 12v test

You can also test the switch, this is from a member here:
3.86v and 3,870 ohms for 2wd
2.94v and 1,090 ohms for 4wd high
1.76v and 357 ohms for 4wd low

So based on the diagram, with connectors unplugged, you can use an ohm meter from pin 1 on "lower" connector, to pin 5 on "upper" connector and should see the above OHMs when switch is in its 3 positions, no need to test voltages, and OHMs are not exact, they are "ballpark" numbers

Key can be off for all tests

Thanks for the input Ron I appreciate it.

So I've got an interesting situation now!! Just got back from work and I thought for the heck of it I'd try to put the truck into 4 Low. Well much to my surprise, it went into 4L! NOW it won't go out of 4L lol!!

Now I've got some fire under me to fix it lol..... Time to start figuring this out!

Well its not the switch if it worked

Tap on the shift motor a few times and see if it starts working again

That sounds good I’ll give that a try. I’m not totally convinced it’s not a halfway faulty switch cause I’m still not getting anything from the solenoid. But who knows maybe it’ll help!

I’m going to start digging into in a few minutes lol.

Well Ron, I started with the low hanging fruit. Disconnected negative battery terminal for a minute. Connected back up and started. My truck cycles through 4H and 4L and 2 wheel drive like it should normally.

Weird. Wonder if it’ll happen again lol...

Yes it will, but at least you know to reset the controller to maybe get it to work again

And it would be the controller, because switch or shift motor just have electrical connections no "circuits" so there is no "reset" possible