My son has a 99 ranger and the 4 wheel drive quit working.Traced it to the front hubs not getting vacumn. If I jump around the vacumn solenoid(not sure if thats what it,s called),the 4 wheel drive works.Anyone have a wiring diagram that shows how this is supposed to work electrically?

 

well i dont think youll need a wire diagram yet. I would have your son put it into 4x4 then 4low. You should hear the motor on the Tcase working. Oh or put ur hand on it to feel it moving. If not the motor could be bad this is a common problem. but then smart thing to do would be to test it for power then use the diagram to find the power wire and test if its getting power. That way you dont waist money on a new motor... Lit us know if this helps and how it gos goodluck

 

when you flip the switch to 4x4 hi the front driveshaft starts spinning but the hubs don't lock,so no 4x4.If I jump the vacumn line to the hubs the 4x4 works.If you flip the switch to 4x4 low nothing happens.The light on the dash stays lit for 4x4 hi.

 

Does this truck have an auto or manual transmission?

The reason I ask is because on my '04, you have to have your feet pushing both the brake and clutch pedals to the floor before switching to 4x4 low (forcing you to be completely stopped) - otherwise, it does what you described above...

Don't know if this also applies to the '99 models, though...

Definitely something wonky with those hubs... I hate vacuum-activated 4WD - AMC used to do that on the Eagles and those things were a major pain-in-the-**** to troubleshoot as they used plastic vacuum lines that got brittle with age and would break - if one of those lines cracked, broke, or wasn't sealed good enough on either end, the 4WD quit working - maybe it's something similar with the Ranger? Dunno...

 

The truck is an Auto trans.It used to work by haveing it in 4x4 hi,put the trans in neutral,turn the **** to 4x4 low,you could hear a few noises in the transfer case and the 4x4 low light came on.This is why I need a wiring diagram.

 

Maybe one of these links will help:

1999 FORD RANGER 4X4: FOUR ELECTRONIC SHIFT..ACTUATOR..FUSES..RELAYS - JustAnswer

1999 Ford Ranger: 4Wd vacume..Signal..you Have A wireing diagram - JustAnswer

http://www.therangerstation.com/tech...ftControl1.JPG

http://www.therangerstation.com/tech...ftControl2.JPG