redpoint5

I'm trying to find the speedo sensor. The Haynes manual says it's located on my transfer case and has orange, black, and blk-light blue wires. I didn't see those colors and couldn't find a part that looked like the picture. Here is the only 3 wire sensor I could find on the transfer case; is this the speedo?:



Also, I'm curious what these lines control. They appear to be vacuum lines. No idea what the electrical connector is either.



Last, I found what appears to be a disconnected vacuum line near the lift pump. Is this needed?



This last lift pump was purchased as a campaign part and lasted only 10k miles! Good thing I had the Juice watching the fuel pressure.

Now I'm trying to decide between buying another stock lift pump and selling the rig, or buying after market and keeping it until Toyota comes out with a diesel. I don't have time to keep wasting on this poorly engineered truck, but I do love the Cummins motor. How much work do the 2003-2004 models demand compared to these 2nd gens?

Tate

Speedo sensor is the ABS sensor in the rear diff. The older 12v's had it in the tranny/t-case.

Vacuum lines in the second picture operate the CAD on the front axle.

Is the vacuum line in the third pic capped off? If so, I wouldn't worry about it. Not sure what it would be for, unless it is supposed to run to the t-case?

sheriffav8r

Should be a green line that is the vacuum vent from the transfer case.

nickg

electrical switch near the shift linkage should be the safety neutral switch (truck should not start if its unplugged)

jnicewan

1. neutral safety switch.
2. speed sensor/output shaft.
3. 4x4 cad vent line. thing on the end is a ck valve to prevent vac/suction

redpoint5

I didn't find my speed sensor on the rear diff.

Jnicewan- are you saying my speed sensor is picture #2 with the vacuum lines? If so I would have never figured it out because my book says I'm looking for a 3 wire instead of a 2 wire.

Reason I'm so interested in finding my sensor is my speedo isn't showing any speed anymore. For a while it would go as high as 30mph when I was doing closer to 65. Now it shows nothing.

Thanks for the help.

TallTom

when my 98.5 speedometer acted up it was the cps located behind the starter.

When the abs light came on and speed o meter completly quit I replaced the sensor located above the drive shaft on the rear end. Its located on the very top, held down by a stud with 2 nuts on it. Take the top nut off and lift on the bracket that holds the sensor in place after unplugging the wires.
It may be tough getting out as it fits tight via a O ring to keep it from leaking gear grease everywhere.

TallTom

redpoint5

After spending an hour under my truck, I was never able to locate the elusive speedo sensor.

For a brief period of time, the speedo reported correctly, but after that it has been flat-lined. Sometimes my ABS and brake indicators will light up, but not very often and they go back out.

Now that winter is here, my grid heaters run a lot since it isn't detecting my speed. I would also love to get my cruise control back.

Where should I be looking? I have searched the T-case and rear differential extensively. Maybe I'm going blind.

Copenhagenjunkie

From Alldata:

Cruise and Vehicle Speed

Vehicle speed and distance covered are measured by the Rear Wheel Speed Sensor. The sensor is mounted to the rear axle. A signal is sent from this sensor to the Controller Antilock Brake (CAB) computer. A signal is then sent from the CAB to the Powertrain Control Module (PCM) to determine vehicle speed and distance covered. The PCM will then determine strategies for speed control system operation.

redpoint5

Thanks Tate and Copenhagenjunkie.

I finally muscled the sensor out of the differential, and now I'm wondering how to tell if it's the sensor that is bad, the wiring, or something else. My wiring is showing 16k ohms and the sensor is also showing about 16k ohms.

There is some wear on the sensor, and I don't know what causes that, or if that indicates it is bad.

smokindodge1996

a abs sensor is tested with a voltmeter on a/c current but you have to have it install on truck to do it put a lead on each side of sensor and turn tone ring if you have an a current while spining its good if nothing the sensor is bad bu that asenso looks bad from the pics its been rubbed against and shouldn't be lookin like that replace sensor and changer rear end oil might have meatl floating in gear oil those sensors go bad all the time i have replaced alot of them in my 13 years as an auto repair tech

lvmknsmoke..

get a airdog. you wont regret it.

torquefan

The end is chewed right off your sensor. I would guess that the speedometer fluctuation has been accompanied by horrific noise from the differential, because it is worn out. Looks to me like the carrier bearings must have a ton of slop in them, causing the tone wheel to contact the end of the sensor while you drive. I would suggest you discontinue driving it intil it is dealt with, or you might end up breaking teeth off your gearset or damaging your differential housing, if it hasn't happened already.

Tate

Pop the cover off the diff and inspect why that sensor is interfering with something inside. The tone ring may have started coming apart, something stuck in teh teeth, fubared bearings, etc. Although if the bearings are shot to the point that it is contacting the sensor, I would expect some noise out of it as well.

schoust

Hey Guy's I'm having the very same problem with my speedo on my 95 and was curriuos on where the sensors exact location is on a truck without Abs?
Sorry Red didn't mean to steal your thread.....