96 sport control trac no awd or 4low all lights/relays working

[gijoecam]

He's a member on here... That's one solution, and necessary if you run a locker up front. But for normal everyday driving, if I was to pull the front axle, I'd simply replace it with a live front axle from any 97-01 4x4, or the live front axle from an AWD '95-'96. It eliminates any of the hassles of the CAD.

 

[quisman]

As of right now I'm hoping it's the CAD. if it's deeper than that or something broken in the pumpkin I will start shopping for a live axle. But from what I've read here and the time I've spent under the rig, it's a pretty simple setup and seems to either work or not....which makes for good easy troubleshooting.
Still concerned about that Voltage tho(broken record). any thoughts...anyone else see this drop.

 

[quisman]

Well, there I was jazzed up expecting to find a oxidized crappy ass CAD
It's in perfect shape an seems to be working perfectly. Reconnected the vac and electrical lines and started it up w/ the CAD hanging down....watched it actuate flawlessly.

For my next trick I jacked the pass side up and lines the splines of the axles together and slid the collar over by hand to engage 4 wheel. When I spin the drive shaft the tire in the air did move freely. I'm assuming the driveshaft is remaining free because lockup is speed sensor based?

This brings me to yet another conclusion. Could I have a jacked up speed sensor?
Watch the video I attached to my photobucket account(uploading, i'll put in next post). When I switch gears I get major voltage drop and as far as I know the only things associated w/ the system are, CAD(only indicator is electric), GEM, Speed sensor, and Selection Motor.
So based on those thoughts, the only thing that would control lockup would be speed sensor and GEM....agreed ?

 

[quisman]

 

[gijoecam]

Well, there I was jazzed up expecting to find a oxidized crappy ass CAD
It's in perfect shape an seems to be working perfectly. Reconnected the vac and electrical lines and started it up w/ the CAD hanging down....watched it actuate flawlessly.

For my next trick I jacked the pass side up and lines the splines of the axles together and slid the collar over by hand to engage 4 wheel. When I spin the drive shaft the tire in the air did move freely. I'm assuming the driveshaft is remaining free because lockup is speed sensor based?

Was the engine idling with the switch set to 4low? The reason I ask is that with the key off, the t-case will be unlocked regardless of switch position. Even with the engine idling and the switch set to 4auto, when stopped, the system activates the clutch at minimum duty cycle, which may not provide enough resistance to keep the transfer case clutch locked. Switching it to 4low locks the transfer case in at maximum duty cycle, but only when you're moving. When stopped, it'll usually drop off to something just over minimum duty cycle. Make sense?

This brings me to yet another conclusion. Could I have a jacked up speed sensor?

I'm not following why you would suspect that yet... I don't suspect it yet... You said before that the front driveshaft turned, but the front wheels did not. If it was a sensor, it would provide other clues (like more often than not, a blinking set of 4wd lights).

-Joe

 

[quisman]

Let me get you some move video of what i see, as far as wheel spin with it in the air.
Out of the ranger and other explorer i've owned I've never even see the voltage drop over the course of a idle switch turn or at slow speed.
I don't so much suspect the speed sensor i'm just looking for something possibly electrical. Did you watch the video? it almost stalls the car out when you put it in gear.
I can totally see why 4low would use move voltage based on the motor changing ratio's.
I'm just about grasping for anything now. I'll try and spend some more time on her tonight.

 

[quisman]

remember, I can get the 6 4x4 blinks when I'm up to speed and it won't engage.
Can i pull the speed sensors out of circuit seperatley?(do they have their own connectors) If so that would certaintly tell me if I have a high resistance load somewhere.

 

[gijoecam]

I did watch the video. I think the voltage drop is a result of the reduction in engine RPMs, not a cause of it. The current draw from the transfer case shift motor is a few amps at most. The draw from the vacuum solenoids is negligible, with a net change of nothing (since you're just switching power from one to the other). The draw from the transfer case clutch coil is a few milliamps at idle, and less than 5 at maximum duty cycle. Hell, the cigarette lighter alone draws 10-15A by itself. The drop you see isn't related to anything except an ailing charging system. Bump the revs up to 1500 or so and see how it acts then.

I know the lights will blink when the CAD is not engaged. It knows it's not engaged. The CAD has a sensor that tells the GEM that the collar is engaged. It won't activate the transfer case clutch until it sees the front axle locked. If it times out waiting for the switch to be made showing the front axle is locked, it'll blink and store a trouble code. You mentioned before that when everything was connected, the front driveshaft was locking, so I don't think we're dealing with the same situation here...

In all honesty, 15 minutes at a dealership or shop with an NGS or WDS scanner and a knowledgable tech, and the problem would be crystal clear. It takes an NGS to monitor the GEM PID's (inputs and outputs). If we could see what the control system is seeing, it would solve a lot of mysteries.

-Joe

 

[quisman]

Awesome joe, Thanks for the clearification.
I'll see what I can come up w/ before breaking down.
I've done tranny's, motors, all kinds of jobs, i'll be damned to lose a 4x4 battle. lol.
I'll keep you posted. thanks so much for all the usefull data.

 

[quisman]

Hey Joe, Question for ya.
Can I bring the GEM itself into the shop for plug and play to retreive the codes ?
I can't really take this thing off my driveway for a couple months unless I have 4wd or she's not comin back up

So, there's a coil inside of the TC that locks/unlocks the fronts correct?

When In for 4low the switch motor engages(the only time it engages) and goes to the low ratio. At this point the coil should also be active to engage the fronts full time as well right ?

So If I'm not seeing fronts anytime, it could be the coil?
Though it will spin by the front shaft by hand, that may be because the CAD is engaged correct?

Do you know of any measurements w/ a dvm to verify the coil and or speed sensors.

Just trying to do what I can here in the mud before I have to ship it to a dealer.

thanks again.

 

[quisman]

question....what's that ?

Also, I just reconnected everything, went around the yard in 4 low and put on ebrake and checked it in gear, free spinning front drive shaft ?

Thoughts?

 

[96eb96]

question....what's that ?

Also, I just reconnected everything, went around the yard in 4 low and put on ebrake and checked it in gear, free spinning front drive shaft ?

Thoughts?

I think that is the g spot, its supposed to tell the abs if you are moving and 4wd is turned on.

 

[quisman]

Cool cool, I'm gonna start playing w/ manual 12V application to the brown to see if I can get lockup someway.
I'm getting airbag code 12 as well, which yields low battery voltage. The more I play around w/ this thing, i'm thinking they may be linked.
Keep'n my head high here

 

[quisman]

So Here is what i'm up to so far...tell me what you guys think.

Got the front up in the air, front axle spins free in any range. Threw a dvm on the brown wire, I never see 12VDC at any point. However, I do have a nice handy near short to ground from the coil to the connector(unhooked from harness). Do I have a bad coil perhaps? From the harness side(disconnected from the TC) I do not have 12VDC in reference to ground either. All my fuses are good, but perhaps I lost a relay during extreme load on the coil ?
Am I making any sense thanks all.