Our Ranger doesn't seem to remember what 4 wheel drive is. The 4WD lights come on/go off at startup, the switch moves, tires are good, but the front wheels are just along for the ride.

Backing up on our 10% grade driveway to grab a trailer is close to impossible now. There was mention of a module, part number 1L54-7H417-AD, being a possible problem, but that was on a 2002, and I haven't figured out where the little darling is located.

If that's the possible culprit can anyone tell me where it is, what it's really called and if it can be bench-tested?

Thanks.

 

Good read here: Ford Ranger 4WD Control Module 1995 - Up

'98-'00 Rangers used PVH(pulse vacuum hubs) on the front axles, this was a poor design and was abandoned as early as '99 on some Ranger models.
The vacuum hoses would crack and hubs wouldn't/couldn't lock.

Read here about troubleshooting that part: Ford Ranger How To: Troubleshoot/Fix Your PVH Hubs (1998-2000)

Read here about manually locking them: Permanently Lock Your 1998-2000 Ford Ranger PVH Pulse Vacuum Hubs

Read here about installing manual lock/unlock hubs: 1998-2000 Ford Ranger Rugged Ridge (AVM) Locking Hubs


1999 seems to be a transition year for the electric 4x4 part, so no firm answer to the module question, if it has one it will be behind the radio in the dash along with the GEM(generic electronics module)
read here: http://www.justanswer.com/ford/4khp9...4x4-liter.html


There are also 2 fuses for 4x4, one in engine bay box and one in the cab fuse box

 

Please check for a vacuum leak, had same problem on a 99 ,very small clear vacuum line on pass side down by the radiator near front of engine

 

Thank you Ron and Scott. I'll scooch under and look at such things.