Ok, the 4wd quit working in my son's truck (99 3.0 3" b.l.). Turned the **** to 4 High (or 4 Low) and the dash light would light up saying it was in 4wd, but it wasn't.

Then, sometimes when switching to 4wd, the light would flash, then stay lit, but still no 4wd.

After some investigation here, we thought it might be the shift motor. Since that is a rather expensive part, we took the truck to Ford for their opinion.

Their service tech said the transfer case was shifting into 4wd, but there was no vacuum to operate the pvh. He said some lines were cracked, one wasn't even connected, and that their starting price to fix the vacuum lines would be $560. So we said no, we can do that.

Our plan tomorrow is start by replacing the vacuum lines, and if that doesn't do the trick, then we will swap out the pvh for manual locking hubs.

Since I am not a 4wd guy (more of a hot rod type) I'm not exactly sure how this works with manual hubs.

1) I assume I have to still have to shift into 4wd with the switch on the dash, and then get out and lock the hubs, correct?

2) If the switch in the truck (which I assume operates both the transfer case and the pvh) is in 2wd, would I still need to switch the manual locking hubs to free or would leaving them in the locked position be okay?

Its kind of a long winded post, but I wanted to give the full picture.

 

The electric 4WD on your year has 2 parts, the electric shift motor on transfer case and the "auto hubs".
The 4WD lights on the dash are connected to contacts in the shift motor housing on the transfer case.
Steady light means transfer case has shifted, flashing light means it hasn't, this could be shift motor issue or 4x4 module issue.
Yes, the 4WD selector also activates the "auto" hubs.

Your transfer case seems to be shifting so most likely issue is "auto" hubs.
The PVH(pulse vacuum hub) was used for 3 years, '98-'00
Good read here in them: Ford Ranger How To: Troubleshoot/Fix Your PVH Hubs (1998-2000)

Yes, changing to manual hubs is a good upgrade, not sure if PVH has that option, as is, through.
When manual hubs are Locked the front axle/drive line will turn, regardless of 4WD selection, this causes lower MPG not alot lower but not 0 either, but 4WD can be engaged without getting out of the truck.
When hubs are unLocked wheels spin free, axle/drive line don't spin, MPG is "normal", but if you want 4WD you will need to get out and Lock the hubs.


This is an article to permanently lock your PVH hubs: Permanently Lock Your 1998-2000 Ford Ranger PVH Pulse Vacuum Hubs

 

Thanks for the input. I have read the first link, but the second is new to me, so that will get bookmarked for later.

Hopefully this will solve the problem.

Thanks again

 

ok, so we replaced the vacuum lines, and that seemed to fix the problem. $7.77 vs $556. That 's the good news. Bad news is now when he shifts into 4wd, the 4 high and 4 low lights flash 6 times then quits, and the truck is stuck in 4 High.

Now what?!

Would that be the shift motor, and how do we get it out of 4 High?

 

So, now we replaced the shift motor, and the lights on the dash are still flashing, and now it won't shift into 4wd at all.

We can't hear the click behind the dash anymore.

So now what?

 

On 1999, check in the engine compartment fuse box, #9 40amp, I believe there are also two fuses in the cab fuse panel for the 4x4, #11 15amp and #17 15amp

Also make sure the new shift motor is plugged in, unplug it and replug it in

The flashing 4x4 lights are generic, usually flash 6 times, no meaning in this, the flashing just means a problem.

Try disconnecting the battery for 5 minutes, this will reset the 4x4 controller, and computer, either can be "****" about holding on to an error, even after the error has been fixed, lol.

 

Well, we let the truck sit for a couple of hours, unplugged and then replugged the motor switch, and now it works!

Thanks for all of the help Ron.

 

If I were you I would have just swapped to manual locking hubs and disconnected the PVH lines. So much easier.

 

$8 for vacuum hose today vs $118 for hubs with a day and half wait, no brainer to at least try the vacuum hose first. And his wheels have center caps he likes, so we had to at least make the effort to keep them. But doing the hubs would have been next on the list.

 

Just for future reference, there is no manual hub conversion for these model hubs('98-'00), you have to change the whole front axle.
You can Lock the PVH hubs permanently through.

 

They do make a manual hub for the 98-00 Rangers. Here's a link to one. Rugged Ridge 1998-2000 Ford Ranger Locking Hubs [15001.70] - $140.95 : James Oaks Enterprises LLC, Specializing In Ford Ranger Based Vehicles

 

Good info, thanks
And not a "break the bank" price either

 

Hello All

I have a 93 Ranger. This is my first one and I'm disappointed and frustrated. I cannot get it into 4-wheel low. I can get it in high, but try as I might it will not go into 4 wheel low.

I'm thinking about putting manual hubs on, and finding a way to put in a stick **** for the 4-wheel drive system.

Any thoughts, comments, or advice will be appreciated.

Jim

 

im not insulting you here so dont take it that way, are you doing it right? stopped, foot on brake?