'94 Ford Ranger 4WD problems

[BamaRob]

My son's '94 Ford Ranger 4WD started acting up a couple weeks ago. First we were going down an old, washed out field road and put the truck in 4-Low. It's a 4.0L V6 with a manual 5-speed tranny. It has push button 4WD and push button range selection -- I really wish it had a manual stick on the transfer case like my old Jeep had. Anyhow, after getting back up the washed out road, I pushed the button to switch back to High range. No problem. I push the button to disengage 4WD, and, as best I can tell, nothing happens. It's still in 4WD and the light on the button is still on. Tried it several more times before just driving it home in 4-high.

Next issue... since it was "stuck" in 4WD, my son didn't drive it for a few days. When he did decide to drive it again, he cranked it and it ran for a few seconds, then he heard (an electrical sounding) pop from under the hood and it died. Restarting it, the engine would race to ~3500 RPM then die. Someone suggested replacing the fuel pump relay so I pick one of those up today at lunch. I'll give it a try this afternoon.

Any ideas on the issue of being "stuck" in 4WD? With the other (seemingly) electrical problems, I'm wondering if there just a switch or relay gone bad somewhere.

Thanks,

BR

 

[Soundguy]

Can't help with the electrical pop.. however on 4wd vehicles.. I've always driven backwards a few feet after shifting to the new range or selecting the new range.

On my yukon.. with a push button selector, it actally won't shift to 2h again untill you run past neutral ( automatic ) and into reverse after you move a fe winches, the lamp pops over to 2h.

I've pretty much been doing this since manual lock in hubs were out.. even though my newer trucks have either shifters or push button.

good luck!

Soundguy

 

[BamaRob]

Thanks, Soundguy. I think we tried backing up a few feet a time or two, but can't be sure. We may have been in a hurry and just didn't remember to go 1st-N-R, back up a bit, then go R-N-1st. If I can get it running again with this fuel pump relay, I'll give that a try.

Thanks,

BR

 

[hunterridgefarm]

Rob, I had a F150 with the push button 4 wheel drive and if putting it it 4 wheel high you just pushed the button. For 4 wheel low you had to push the button for 4wheel drive and put it in neutral for it to go in low range, and you have to put it in neutral to get it out of low range.

My F250 has the stick lever for 4 wheel drive and to get it in low range I have to put the truck in neutral and the same to take it out.

When you put the ranger in low range did you put it in neutral or is it different for a manual transmission?...both my trucks were automatic trans.

 

[HGM]

The "shift on the fly" systems are famous for being a little unreliable if not used much. The motor on the side of the transfer case will become dirty and sometimes it will work, sometimes it wont.. The quick fix if you are stuck in or out of 4x4 is to tap on the motor and try again.. The motor aint cheap, so you'll have to decide how important it is...

As for the electrical issue, unless there is a little more to the story, it doesnt sound like a relay.. But anything is possible..

 

[DieselPower]

The "shift on the fly" systems are famous for being a little unreliable if not used much. The motor on the side of the transfer case will become dirty and sometimes it will work, sometimes it wont.. The quick fix if you are stuck in or out of 4x4 is to tap on the motor and try again.. The motor aint cheap, so you'll have to decide how important it is...

As for the electrical issue, unless there is a little more to the story, it doesnt sound like a relay.. But anything is possible..

I would have to agree. The motors on the transfer cases are not the most reliable thing Ford ever used. I have replaced more of them than I want to remember.

As for the starting and revving up I to highly doubt it is the fuel pump relay. You either have fuel or you don't.

 

[QueBota]

Good info here.

http://www.explorerforum.com/Singleton/web/pages/tcase.html

Dave

 

[BamaRob]

Update...

You guys were right about the revving/dying problem not being the relay. I got home yesterday afternoon and put the new relay in. Cranked the engine and it fired right up, revved to ~3500 RPM, and died. I cranked it again and started tapping the gas pedal. It would stay cranked, but wouldn't idle. I got back under the hood and discovered 2 vacuum lines weren't attached. I reattached one of them and the idle smoothed out. I couldn't find the other line and just plugged the other vacuum port. The truck is running like a champ, but I need to consult an owner's/service manual to figure out what supposed to be connected to that other vacuum line. The light on the 4WD button is still lit, though I'm not sure 4WD is actually engaged.

No chance the 4WD is vacuum actuated is there?

Thanks,

BamaRob

 

[HGM]

On the radiator support, you should have a vacuum diagram for that vehicle specificly. Its sometimes hard to read though.. The vac lines arre typicaly foolproof, meaning that it will only route to one location properly.

The transfer case has no vac going to it, its electrical. Did you tap it with a hammer?

 

[RobertN]

No chance the 4WD is vacuum actuated is there?

Probably not. It was GM that used the vacuum system on the S10 pickups and Blazers.

 

[BamaRob]

The transfer case has no vac going to it, its electrical. Did you tap it with a hammer?

Not yet. I'll try that this afternoon.

Thanks,

BR

 

[HomeBrew2]

Continuing what HGM said, I have also read that sometimes the motor can be simply removed, cleaned or just unbolted and bolted back up (any or all), without having to replace the motor, if tapping it doesn't work.

As preventative maintenance, I "excercise" my xfer case motor weekly just driving out my gravel drive.

 

[Phils]

When a family member bought an older Explorer there was a problem with the 4WD engagement system. Some shops said they had to replace the motor. A shop where I knew them well replaced a "pin" that was made out of nylon or something similar. It took a special tool that they had rigged, but was a cheap fix and worked fine thereafter.

Sorry I can't give more details, it was a few years ago. They talked like it was a common problem and that without their "tool", motor replacement was the only fix. If it comes down to it I can PM you their phone number and the name of the mgr that knows the fix.

Phil

 

[cp1969]

Update...

You guys were right about the revving/dying problem not being the relay. I got home yesterday afternoon and put the new relay in. Cranked the engine and it fired right up, revved to ~3500 RPM, and died. I cranked it again and started tapping the gas pedal. It would stay cranked, but wouldn't idle. I got back under the hood and discovered 2 vacuum lines weren't attached. I reattached one of them and the idle smoothed out. I couldn't find the other line and just plugged the other vacuum port. The truck is running like a champ, but I need to consult an owner's/service manual to figure out what supposed to be connected to that other vacuum line. The light on the 4WD button is still lit, though I'm not sure 4WD is actually engaged.

No chance the 4WD is vacuum actuated is there?

Thanks,

BamaRob

According to my Haynes book, Ford put pulse vacuum hubs on the 1998-2000 year models, so the 1994 should have been something else.

Are you sure it is locked in? Turn some sharp corners with it on dry pavement--if it doesn't buck, you are not locked in. If you're not familiar with that technique, jack up the front and rotate the wheels and see if they are locked.

The revving sounds like a dying MAF sensor to me. That is exactly what my '98 did except it never came out of it. It would start, rev, then die. Does the '94 have an OBD plug on it?

 

[Soundguy]

The comment about periodically 'exercising' your 4wd is a good one. I try to shift to 4wd 1x per month just to keep it moving. When i had a 4x4 tractor, i did the same..

soundguy

 

[TractorLegend]

my crystal ball says the shift motor is bad---it looks like a wiper motor bolted to the back of the t/case