Hi there I have a 2008 ford ranger with the electronic 4x4. I will save you guys a few headaches by answering these general questions.

Now the 4x4 will engage from time to time but then others it will not engage at all and will not show any light in the dash.

1: when I start the truck the 4x4 lights come on in the dash (in theory it can't be the 4x4 pcm from what I understand)
2: I replaced the transfer case motor its brand new
3: all the fuses are good so are the relays
4: I've been told that the switch in the cab that you turn for the 4x4 to go on does not fail since its only small resistors...

if anyone can help me out that would be great thanks!

 

The 4WD lights coming on with Key on is a BULB test, all the lights in the dash should come on so driver can see if one is burned out, so nothing to do with the system the bulb is for, in this case 4WD system

Correct the dash switch never breaks unless hit REAL HARD with a hammer, lol

The 2001 to 2011 Ranger used a newer 4x4CM(control module) these are a known issue, they were redesigns in 2006 but still had issues

In a 2008 Ranger the 4x4CM will be behind the radio so not easy to get to

The 4x4CM has 2 relays inside, and when it was working you should have heard it "CLICK" when you changed the switch position
The relays power the shift motor then cut power when its in correct position, so click...............click

If you don't hear this then 4x4CM is most likely the problem...........if you have checked the fuses, no power no click, lol

If the 4x4CM clicked and then clicked again very fast and 4WD lights started to flash, that would mean the shift motor wasn't moving

So no click and no flashing 4WD lights would point to 4x4CM issue

The 4x4CM label will look like this on yours: https://cimg3.ibsrv.net/gimg/www.ran...557c48fc40.jpg

The Ford Part number is at the top 8L5A-7H417-AA
8 = 2008
5L = Ranger
A = electronic department

7H417 = Ford part number for any 4x4 control module from any year or model

AA = revision number, AA would be first batch, lol, best to get AB, AC, AD or AE as replacement, the later the revision the better

You are better off with a new one since these are KNOWN to fail, but new are getting scarce because they did fail, so you can try a used one, try local wrecking yard and see if they will replace it if it doesn't work, which is tough for electrical parts but its free to ask

Must be for 2007 to 2011 Ranger, the earlier model(2001-2006) will not work in your 2008

 

Hey RonD! Thanks for all of this information that's what I thought it was but wanted to get someone else input on it and to make sure haha!

So I will be looking into getting a new 4x4cm and changing it out! I will keep this post updated once I get the parts and its all changed out for other people to check and confirm if they have the same issue as me!

Cheers.