Hi I have a 2004 dodge ram 5.7 quad cab when I put it in 4 wheel drive the light doesn't come on Can someone tell me if it is the sensor and where it is located Thanks

 

Any info on this would be great! I locked mine in today while playing in dads field and my light did not come on. I was worried for a min b/c i thought there was something wrong with the 4x4. That was not the case. Everything worrks fine i just dont have the indication light.

 

I've still got this problem.....anyone got an idea? I traced the wires and jiggled the connectors but everythings seems straight...

 

The light only turns on if there is a problem with the 4x4... It explains it in your manual

 

What? You mean the part where it says the 4WD light alerts the driver that the vehicle is in four-wheel drive? Is it opposite day again?

 

Actually your right! I meant to say the serv 4wd light. I just noticed that my light when I engage the 4wd the light does not turn on either....

 

The light should come on when you engage the 4x4. The part you need is the transfer case position sensor. Its 30 bucks at the dealer and is directly on top of the transfer case. Very easy to change. Took me 5 minutes once I dound the sensor. The dealer told me I couldn't do it without a lift. Ha, I laid on a rug under the truck and did it in 5 mins.

 

FROM THE SERVICE MANUAL, Page 21-443

POSITION SENSOR
DESCRIPTION
The transfer case position sensor is an electronic
device whose output can be interpreted to indicate
the transfer case’s current operating mode. The sensor
consists of a five position, resistive multiplexed
circuit which returns a specific resistance value to
the Powertrain Control Module (PCM) for each transfer
case operating mode. The sensor is located on the
top of the transfer case, just left of the transfer case
centerline and rides against the sector plate roostercomb.
The PCM supplies 5VDC (+/- 0.5V) to the sensor
and monitors the return voltage to determine the
sector plate, and therefore the transfer case, position.
OPERATION
During normal vehicle operation, the Powertrain
Control Module (PCM) monitors the transfer case
position sensor return voltage to determine the operating
mode of the transfer case. Refer to the Operating
Mode Versus Resistance table for the correct
resistance for each position (Fig. 87).

OPERATING MODE VERSUS RESISTANCE
SENSOR POSITION OPERATING MODE SENSOR RESISTANCE (ohms)
1 2H 1124-1243
2 4H 650-719
3 NEUTRAL 389-431
4 4L 199-221
5 NOT USED 57-64
REMOVAL
(1) Raise and support the vehicle.
(2) Disengage the transfer case position sensor
connector from the position sensor.
(3) Remove the position sensor from the transfer
case.
INSTALLATION
(1) Inspect the o-ring seal on the transfer case
position sensor. Replace the o-ring if necessary.
(2) Install the transfer case position sensor into
the transfer case. Torque the sensor to 20-34 N·m
(15-25 ft.lbs.).
(3) Engage the transfer case position sensor connector
to the position sensor.
(4) Lower vehicle.
(5) Verify proper sensor operation.
Fig. 87 Position Sensor Linear Movement
1 - POSITION 1 - 10mm ±0.5mm
2 - POSITION 2 - 12mm ±0.5mm
3 - POSITION 3 - 14mm ±0.5mm
4 - POSITION 4 - 16mm ±0.5mm
5 - POSITION 5 - 18mm ±0.5mm
6 - POSITION 6 - 20mm±0.5mm - FULL EXTENSION
__________________

 

My serv light came on, and the lights on the dash switch went all off. The 4x4 wouldn't work any more. Here was my fix:

The wire harness connected to the transfer case was hanging down and sitting on the driveshaft which wore through the wires. I fixed the 3 wires that were broken, and all is working great now.
Thought you might want to know.