'01 4 button NP8, should there be constant pwr at the TCCM?

[mike2004tct]

Since I've been having problems with my 4WD,http://www.automotiveforums.com/vbul....php?t=1055873
Something has been draining my battery. 2 y/o battery died. Voltage reg. outputs over 14V.
Last week, I bought a brand new battery. Parked the truck Friday, went out today, and the battery is completely drained.

I disconnected the TCCM today, and noticed I had 12 volts on the orn power wire with ignition off. Also notices I had 14.5V with engine running.

Is the TCCM draining it?

[MT-2500]

Originally Posted by mike2004tct

Since I've been having problems with my 4WD,http://www.automotiveforums.com/vbul....php?t=1055873
Something has been draining my battery. 2 y/o battery died. Voltage reg. outputs over 14V.
Last week, I bought a brand new battery. Parked the truck Friday, went out today, and the battery is completely drained.

I disconnected the TCCM today, and noticed I had 12 volts on the orn power wire with ignition off. Also notices I had 14.5V with engine running.

Is the TCCM draining it?

The module has 2 hot all time feeds from ATC fuse Pin d-14 and D-15 orange wires.
Also some 12 volt ign on feeds.

To check if it is the module draining battery hook up a amp draw tester on battery and pull ATC fuse and see if amp draw changes.
If no change start pulling other fuses and power feeds.

Amp draw after about 15 minutes computer power down should not be over .025 milliamps.
If much over that you have a short or to large amp draw.

Post back amp draw test.

[mike2004tct]

Bad alternator (Vreg) was the drain. Bearing was shot too, but the unit still charged. So, changed it out.

Now, back to the 4WD.
Still stuck in 4WD but only rear wheels driving. selector buttons won't shift to 4Lo, or 2 Hi.
After checking vacuum on the two actuators, I crawled unit the truck right after pushing the 2Hi button. Grabbed the motor case of the TCM, and felt it rotating. So, the TCCM works, the TCM works, but the unit switch goes back to 4Hi although truck is in 2wheel drive (rear only). The Service 4WD light comes on.
I don't have a code reader for this, only a pocket scanner for the engine codeds.

[MT-2500]

Originally Posted by mike2004tct

Bad alternator (Vreg) was the drain. Bearing was shot too, but the unit still charged. So, changed it out.

Now, back to the 4WD.
Still stuck in 4WD but only rear wheels driving. selector buttons won't shift to 4Lo, or 2 Hi.
After checking vacuum on the two actuators, I crawled unit the truck right after pushing the 2Hi button. Grabbed the motor case of the TCM, and felt it rotating. So, the TCCM works, the TCM works, but the unit switch goes back to 4Hi although truck is in 2wheel drive (rear only). The Service 4WD light comes on.
I don't have a code reader for this, only a pocket scanner for the engine codeds.

4W with the auto matic button on transfer case shifter buttons?
If so.
Lot of problems with the shift button switch.
You should be able to OHM it out on button switching.
But.
Best to find a repair or transmission shop that has a transfer case capable scanner and get codes and run the shift test built into scanner.
If you can get any codes post back code no.

[mike2004tct]

Originally Posted by MT-2500

4W with the auto matic button on transfer case shifter buttons?
If so.
Lot of problems with the shift button switch.
You should be able to OHM it out on button switching.
But.
Best to find a repair or transmission shop that has a transfer case capable scanner and get codes and run the shift test built into scanner.
If you can get any codes post back code no.

Yes, 4 button switch.

I've been putting off taking it in to be scanned, but I'm out of options other than the switch. Because the lights flash for all 4 buttons, I figured the switch is ok, and the relays are clicking away - another clue that the switch is working properly (I'll guess they're just momentary,definitely not tactile, and the relays latch to light the switch constantly)

[mike2004tct]

Well, I figured it out last Tuesday.
All of a sudden, my battery drain is back. Disconnected the TCCM computer for a week, battery drain goes away. Everytime I plug the computer back in, or disconnect and reconnect the battery, I hear the TCmotor run for about 3 seconds.
Finally had a day nice enough (warm ~30 degrees) to crawl underneath and take the TCMotor off. The motor would run when I pushed buttons, but nothing would change on the Transfer case. button stuck on 4WD high, but truck is in 2WD. Front shaft from TC to front hub is locked, so I know vacuum is good and front shafts are locked.
Dropped the TCMotor, and noticed I could turn the slotted receptacle for the TC shaft by hand. Not good.
Ordered a new motor Wednesday, got it today and put it in (came from PA., got stranded by the East Coast storm). Had to turn the TC shaft slightly to get it in neutral. buttoned everything up, and it works. Took a 5-10 button pushes from 4H to 4L to 4A to 2W before it finally shifted out of neutral. Had me worried for a bit, thought I'd have to take the motor off and shift the TC by hand.
So,apparently the old TC motor gearing is stripped. I can turn the fitting with my pinky (and I'm getting weaker the older I get) Apparently, the motor must have been running continuously, in order to drain the battery if it sat more than a day.

So, we're in the process of a 3 day storm here, 20" of snow predicted.
I have no excuse not to go to work tomorrow.