installed new bw4405 now no 4wheel drive

[umd pru]

hey all,
i was wondering if someone here can gimme a hand diagnosing my problem. the tcase in my explorer blew a few weeks ago so i bought a rebuilt unit to swap in. i swapped it in the other day with one small problem...the brown wire coming out of the transfer case. I couldnt figure out how to get the end of it out of the wiring harness plug so i cut the wire on the new tcase and spliced it into the harness. well, now the 4wheel drive isnt working at all on it. i assume that the brown wire is used to actuate the clutch pack inside the tcase so i think that maybe my splice job isnt cutting it. i scanned the ex and it doesnt have any codes. maybe the shaft speed sensors i swapped over from the junk tcase are bad? the 4wheel was working before the swap. any help?

pru

edit: is there somewhere i can get a schematic and or voltages that should be present at the pins, or resistances? i have access to a repair website but they only talk about using scan tools to retrieve trouble codes and my ex does not have any.

 

[rmcknight]

are you saying you have no front wheel drive, but you have rear wheels turning? The brown wire will effect the front wheel TOD split from 30% to 0%.

 

[umd pru]

correct, the rear wheels are fine, i can drive it around all day as is. the front wheels are not turning under power when in 4wheel drive, they are just free wheeling. i know this because the left front cv joint is junk and makes all kinds of noise when turning under power.

 

[rmcknight]

OK, then, Hmmmmm. There is a troubleshooting section in the manual on this but i'm at work. Do you know what year the TOD transfer case vehicle was from, i think on the older ones the brown wire was earth or open, but on the newer ones it has a feed back signal that indicates what mode its in.
Have you got one of those CD Manuals (ebay at about $10).

 

[umd pru]

I have access to Snap-On Shopkey 5 and im going to follow the trouble shooting as much as i can. Basically, im gonna check the TOD relay and then check the voltages on the brown wire. the manual says it should be 10+ volts. If thats present at the brown wire at the tcase, then the TOD clutch is defective. I know for sure that this is the correct tcase for my vehicle. its a 1997 xlt v-6 SOHC. I matched the model numbers up on the tcase before purchasing it. Anyways, i hope to get to this stuff tomorrow, ill let you know what i find. any other help or suggestions are greatly appreciated.

pru

 

[gijoecam]

Simple way to check it. Use a good 12V test light with a sharp tip on it. Turn the key on, and flip the switch to 4high. Then, crawl under it and check the brown wire for 12V before and after your splice. That'll tell you right away whether or not you've got power there.

Now, if you've got power to the t-case, and it still won't engage, check to make sure you've got a good ground from the t-case back to the battery. Also, you might want to unplug the connector down at the t-case and see if you've got continuity to ground through the transfer case clutch coil and the transfer case housing.

If you've got power flowing through the clutch coil, but the t-case isn't engaging, you got a bad t-case.

-Joe

 

[umd pru]

I checked the voltage on the brown wire, it was reading 5.75 volts. i raised it and put it into 4wheel and both of the shafts were locked together. took it out of 4 wheel and the shafts were free to turn either way separately. Last night it snowed a bit so i took it to a parking lot and stomped on the gas on top of the snow. the rears were spinning away and the front were being intermittenly powered through the tcase when the switch was in auto. in 4 wheel , the fron twheels were spinning as fast as the rear. i think the tcase is working fine but for some reason im not getting 10 volts, only 5.75. thats causing it to partially engage but not send all power to the front because with the blown tcase on there the front left cv joint would make all kinds of noise when under power. anyways, now i gotta figure out why im not getting 10 volts. probably a bad ground. ill let you know what i find out.

adam

 

[rmcknight]

I looked up the pinpoint tests, you should get no more than 10 volts, and > 0 volts when activated, so id say 5.75 is ok? there are some more tests relating to resistance of 5 ohms but the diagrams are graphical.

 

[umd pru]

according to snap-on's shopkey 5, it states that a voltage of 10 volts or less is a problem. the voltage needs to be above 10 and obviously wont go above 12 or so. a voltage of 10 or less probably doesnt engage the tcase clutch completely and lets it slip while operating which is no good. im gonna do some more troubleshooting tonight, ill let ya know what happens.

pru

 

[rmcknight]

when off, 0 volts
when on 0 to 10 volts,
it actually says >10 volts is an issue with the some other part (I think it was some sort of control relay), and that needs replacing?