Four wheel drive will not engage

It sounds like a pain but I had the same problem and instead of buying the expensive hubs I bought the rough ridge manual locking hubs they are only like $150 for the set of two, you can find them by searching them on google, good luck

The dome light quit working and the electronic shift control for the 4x4 stopped working also, everytime I replace the fuse it keeps blowing it.

Found the problem was a relay up under the dash causing the problem in a little black box taped up

Went to autozone picked up a new relay everything is working fine now, thanks for the help.

I have a 99 Ford Ranger XLT 4.0L. I turned my switch to 4wHi and I can hear it engage and my front drive shaft turns but the front wheels do not pull. When I turn the switch off the front drive shaft stops turning. The other day when I turned the switch it almost sounded like a "ratcheting" sound which I am assuming were the auto locking hubs. I am just not 100% sure what it may be. Any help is greatly appreciated. Thank You

1999 Ford Ranger mileage: 54,000. I am having trouble engaging the 4x4 wheel drive. When I press the 4x4 button, I hear a tick, tick, and tick from the computer behind the drivers seat, hidden behind the jump seat. I hit the reset button and that got the light that tells you the 4x4 is engaged to come on but the wheel did not engage and pull when I spun the back wheels. I reset the computer again and again but the wheel never engaged.

Try replacing the engagement motor on the transfer case

99 ford ranger 4x4 auto tran with turn **** switch for engaging 4x4 when I switch from 2wd to 4wd the lights on the dash come on but the wheels never engage or does kick in. No sound. What should check to fix this

I have a 1999 Ford Ranger 4wd will not work sometimes it engages and some times it won't also the 4wd and 2wd light in dash will blink 6 times how do I fix this?

If this was a constant problem I would say it is your front hubs. 98 and 99 have PVH that breaks quite often. Mostly a vacuum leak from one of multiple locations, 1) the o-ring seal on the hub 2) the seal from the axle bearing to the interior of the axle 3) any of the vacuum lines running to the hub.

1999 Ford Ranger XLT 4x4 off-road 4.0L
When I engage the 4x4 through the electronic switch the electric motor on the transfer case DOES engage the 4H and 4L, I know the electric selinoid is working, however I do not get any power to the front wheels. I notice a metal on metal scraping noise coming from under the vehicle, I can't tell if its coming from the transfer case or the front end of the vehicle. I used the 4x4 all winter and at some point it stopped working, I am not just sure when. All I know is that I have no power being tansfered to the front end and I have a scrapping noise. I had a vaccum leak repaired a few years back and I haven't had that kind of problem since.
Please provide suggestions.

"Check the U-Joint. If it's good you need to look inside the pumpkin! Or pull the wheels off and check the cheap plastic stuff at the wheels!" - Merlin2021

No offense Merlin, but if were a U-Joint wouldn't I hear metal scraping all the time? I only here metal on metal when I turn the 4H or 4L on. I can be driving in 2H perfectly with no noise or scraping sound and then switch to 4H(shift on the fly). Then I get no power to the front wheels and the scraping noise starts. Then I switch back to 2H(shift on the fly again) and the scraping noise stops and throughout the whole time I got no front end power.

I hope that this clearifies my situation a little better.

Thanks

I'm sorry I haven't looked into the guts of it yet.
I was just trying to get an opinion on if someone thinks that it could be gummed up hubs or if the front drive axel could be broken some how, or other ideas. I will be looking into it this weekend.
I try to fix these things myself, but there is only so much you can get from a book or read off forums, so I thought that I should ask.