Transfer case causing battery drain

[JSchuricht]

So I am trying to find the source of a battery drain in my 00. Tracked .064a down to pin 9 of C240a on the GEM which from the description should be a ground return when the transmission is in N and the transfer case is in a position that isn't documented in my manual. What I have found is a vary unstable +5v in reference to ground coming from the transfer case. I get +6v from the transmission in N. My big question is should this be a ground and what output should I be getting from the ESOTF transfer case in each position?


Key off, transmission in P, transfercase in 2WD

Transmission in N

Transfer case C285b disconnected

[NoRalPh]

I'm trying to think, what electrical connections are there in the TC?

There's the motor (on the ESOF equipped) but, no sensors right? If you unplug the motor and it drops you could concentrate there maybe. If not, wiring? The GEM itself?

Also, what could be special about Neutral? I mean, the NSSW would be the same in Park too.. Is there a second sw for the ESOF to be satisfied for it to go into 4WD-L? Where's that located? Could that part of the issue? That sw enabling the motor to then be able to move into that position?

I wish I had a clearer understanding on what this all does (I have a manual TC). It always helps to know "Why something works" to know "Why it isn't"

[Sticker Monster]

this may help you diagnose your issue...

SM

[JSchuricht]

It's the transfer case encoder. 6 conductor; contact plates A-D, VCC and encoder ground. I don't think it connects to the motor, it just tells the GEM what position the transfer case is in and if the transmission is in N so it can go to low.

It's going to be a few days before I can get back to it but from the stuff I have checked, it doesn't match what the pinpoint tests show. The weird thing is the transfer case works. I am thinking it has to be the GEM, it's the only common component between the DTR and transfer case, just wish I knew how the contact plates worked in the transfer case. Might be time to start looking for a manual transfer case, would probably cost as much as the GEM.

[JSchuricht]

Well this thing is getting the better of me. Installing a relay to open C240a pin 9 to the GEM when the key is off and looking for a NV271 with linkage and shifter.