4wd in a 97 sport wont work

[twisted064]

ok guys here it is... i have a 97 sport that the 4wd doesnt work i have replaced the transfer case w/ a new one as well as the transmission. as well as replacing the bearing casets in the front end just in case that might affect it, suprise, suprise it didnt... but i am hoping that someone might have another suggestion. FYI i know all about the Brown wire mod and DONT WANT to do this i just want the 4wd to work . ANY SUGGESTIONS?????????

 

[gijoecam]

Does the light for 4high come on when you flip the switch?

Does 4auto work?

Can you engage/disengage 4low?

We need some more information about the system and what it is/isn't doing to be able to troubleshoot it. Telling us 'it's not working' doesn't help much.

Given that you've replaced the transfer case and it still doesn't work leads me to believe it's likely an electrical gremlin we need to chase down, but we first need to know what it is or isn't doing.

Start there and we'll see what we can figure out.

And don't worry about the brown wire mod... that's not the place to start here.

-Joe

 

[twisted064]

hey thanks for the reply yes the truck will switch in and out of 4hi,4low and auto all the dash lights come on and off correctly.. in essence as strange as it sounds the truck does everything just like it should EXCEPT actually go into 4wd

 

[Charlie]

How have you tested it to make sure it isn't in fact in 4wd? When you put it in 4wd low, do you hear a "clunk" sound? Also, when putting in 4wd low, you have it in neutral, stopped, with the foot on the brake, right?

 

[twisted064]

hey again thanks for the thought but as i stated it does engage the new transfer case and i have tested it and know for sure its not engaging the front axle so any another ideas ??? anyone??

 

[Charlie]

Hmm, I had thought it could be the vaccum disconnect..but that was only on 95's and 96's. I'm fresh out of ideas.

 

[brewman]

from listening to your symptoms i'd say you have no voltage going to that brown wire or the gem ground is faulty.

A bad fuse, gem, wiring, front, or rear driveshaft sensors, ecm, could all effect this problem

the way it seems on these 97's is that in order to have the variable electromagnetic hub lock the front driveshaft in place in the transfer case. that brown wire needs to be carrying voltage from the gem module to the transfer case. from what they say it should be easily accessed behind the radio in the dashboard.

If you take a voltage tester and probe the brown wire while the selector is in 4x4 low in neutral with brake on, it should read voltage to ground. if no voltage, it sounds like you could cut it and take the lighter feed and energize the brown wire going to the transfer case, but ask one of the experts first. If it locks in, you know the gem module isn't feeding voltage to the magnet. those hall sensors make the torque on demand module vary or pulse the voltage to adjust the magnet for applying full to all locked front driveshaft to low voltage slippage of the front driveshaft.

at that point the easiest way would be take it to ford so they can read the error codes. the ecm reads the sensors signals so the gem may be fine, and one of the sensors may be bad, or the tod may be bad, or just a bad wire

If you want to spend around three hundred bucks, I think autotap obd ll/can has fords extended software that reads these codes. But a ford dealer is cheaper