92 XJ NP231 to NP241J Wiring Question

[nosigma]

Been reading a lot of threads on this along with doing some google searches but have not found a solution. Seen a lot of posts that say "its on search" but no luck.

Vehicle is a 92XJ (OBD1). Transfer case is a TJ NP241J 4:1 ratio.

Question is how to hook up the wiring for the speed sensor.

92 XJ is two wire: White & Black
NP241 is three wire with a connector between the transfer case speed sensor and the chassis harness. Chassis harness side is Yellow/Pink, Blue & Blue/Red. Transfer case side of the connector is Orange, Black, Tan

I have seen three general descriptions of what to do, but non of them were specific or were posted by anyone who appears to have done the swap. Suggestions were:
1) Splice wires (no description of what to splice)
2) Splice wires and add a 5V power wire (no description of what goes where)
3) Swap in doorman part from a GM for the speed sensor (no mention of what year the rig was, OBD1 or OBD2.

Looking for some specific guidance.

John

Pics of NP241J connectors below

NP241J wires coming from the speed sensor Orange, Black, Tan


NP241J wires coming from the connector (chassis side) Yellow/Pink, Blue & Blue/Red

 

[nosigma]

Studied several 92 XJ wiring diagrams.

Some 92's have a VSS with 3 wires, others have a distance sensor with 2 wires. I have the distance sensor. On the distance sensor the white wire goes to the instrument cluster so this must be the speedometer signal wire. The black wire on the distance sensor carries +5V and is on the same 5V supply as all the engine sensors.

The TJ NP241J 4:1 transfer case uses a hall effect sensor. The output shaft has 3 large teeth each of 60 degrees duration. Not sure what the three wires connect to yet.

John

 

[Vanimal]

you'll probably need a signal converter, like a dakota digital sgi-5. That's what i run on my 91 (2 wire sensor)

 

[nosigma]

Vanimal
Thank you. Do you remember how you happened to hook it up, as a multiplier or divider and how many ppm you went from (rubi box) to how many ppm you converted to (speedometer)?

For $85 I am going to order it up.


I got the Wiring for the sensor.....
Looked up VSS wiring for 03, 04....to 06 TJ rubicons. Hit the jackpot on the 04. Thread on correcting speedometer. Wires coming from the NP241J VSS sensor are:

Red: 5V
Black: Ground
Tan: Signal.

 

[Vanimal]

i have a jk 241or with an adapter i made to add a speedo sensor, which happens to be a hall effect type from a toyota. i don't recall the wiring or settings, but it wasnt too hard to figure out.

 

[nosigma]

Kastiens various VSS threads state that XJ run at 8000 pulses per mile and 1000 drive shaft revolutions per mile (OEM). Several web searches gave the same info and also indicate that TJ's and XJ's run at 8000 pulses per mile and both use a 5V sensor. So I may just be able to wire this up by running the sensor tan wire to the speedo drive white wire, XJ 5V input (black) to sensor red and then ground the sensor black.

I can see where the converter would be essential if you set it up for something other than 8 pulses per revolution (your set up?). I am not sure that I need a converter though looking at the sensor and the tooth count on the rubicon box I cant see how 8 pulses per revolution are generated by 3 large teeth, 6 pulses (one per edge/field change) or 3 pulses (one per field collapse).

Guess I will just give it a try and see what happens. If I need to recalibrate the Dakota Digital box is cheap enough.

John

 

[Vanimal]

you can try it, but it did not work for me. i forgot the specifics why, but i had to use the dakota digital box, and it had nothing to do with the counts per rev or calibration.

 

[nosigma]

you can try it, but it did not work for me. i forgot the specifics why, but i had to use the dakota digital box, and it had nothing to do with the counts per rev or calibration.

Hmm that would suggest the signal characteristics are wrong, 5V pulses versus "ground" pulses where 5V is switched off for the "ground" pulse. Converting from the reed switch to the Hall effect device may introduce such a change in singal characteristic. The Dakota box instructions didnt say anything about signal conditioning just pulse count corrections though it does discuss 2 lead (reed switch) versus 3 lead sensors (Hall effect).

Since you had this experience and I will have to recalibrate the speedometer (changing gears and tires) I will go ahead and order the box now.

thanks again

John

 

[souske]

x2 on the SGI-5, worked great for me

 

[unhitched]

I used this write up
http://www.naxja.org/forum/showthread.php?t=1063946&highlight=241or&page=2

which states

So, I cut of the connector on the XJ and terminated a weather pack connector on the leads.
Quote:
Originally Posted by Seiler
The 3 wires on my Jeep are:
Violet/Orange: +5V
Black/Yellow: Sensor Ground
White/Orange: Speed Sensor Signal
Thanks Scott
The Rock Trac Transfer case is:
Brown: +5V
Black: Ground
Orange: Speed Sensor Signal

this worked great for me, I did not need anything else, my speedo was within 2 mph, but mine is odbII,

 

[Vanimal]

he has a 2 wire stock speedo wire... that wont work.

 

[unhitched]

sorry i did not know... just sharing what worked for me

 

[nosigma]

unhitched,

Dont feel too bad. Someone else may be able to use the info.

There are a lot of threads on this this topic but almost AFAIK none of them actually gave the solutions.

John

 

[nosigma]

So I got the Dakota Digital SGI-5C box installed and I am not having any luck getting the speedometer to read.

Wiring from NP241J (wire colors are sensor to connector)
Red: 5V in
Black: Sensor Ground
Tan: Signal

Wires to XJ computer/speedometer
This is a 92 XJ that uses a two wire sensor (distance sensor) stock.
White: 5V (used to run power to the NP241J VSS red lead)
Black: Signal (takes output from the Dakota Digital box)

SGI-5C set up
Power: 12V Accessory feed from fuse box with fuse
Ground to chassis (good ground)
Sensor Ground: NP241J VSS sensor ground
Input: Tan wire from NP241J
Out1: Black wire that use to run to the XJ distance sensor.

I called Dakota Digital and they suggested application #2
This calls for all dip switches to be in the off position:
SW1 Off: box is used as a signal generator speed input
SW2 Off: Sensitivity is high
SW3 Off: 4k-16k pulses per mile (ppm) input (correct for Jeeps which are 8000ppm)
output 1 is 8000 ppm AC (what I am using)
output 2 is 8000 ppm oc (open collector, switching to ground, square wave)
SW4 Off: slow output.

When powered up the red light is off and green light is on constant. This indicates power on and no speed signal present. Which is what I should see.
When engine is running and in gear the red light is off and the green light is constant. This indicates power is on with no speed signal present. This is not what I should see. There should be speed signal present and the green light should be flashing.

I have ohmed out the leads. The Tan signal wire is indeed the input signal being used.

Right now the only thing I can think of is that the VSS is bad. The tan wire is showing 3V but not having an oscilloscope I dont know if its a constant 3VDC or a chopped (square wave) DC signal.
I did try using output 2 to send a square wave back to the speedometer. No joy. But the problem seems to be on the input, not output side.
Any suggestions from those who have used the SGI-5?

John

 

[nosigma]

Another question: The wiring diagram I have shows the white wire going to the instrument cluster. While it carries 5V, is the cluster looking for a rapid grounding of this wire by the distance sensor to create the pulses that are read by the speedometer?

John

 

[nosigma]

I decided to run a dedicated 5V line from the FI system (pulled from the MAP sensor input) to the VSS. Wanted to see if I could get an input signal (green light flashing) from the DD SGI-5C. Still no signal. Ordered up the VSS. Pick it up when I get off TDY.

John

 

[nosigma]

Of course I got a geared VSS from trak auto and the np241J uses a magnetic pick up. The magnetic pick up is back ordered everywhere so no joy on that part. I tried a bunch of different wiring combo's and no matter what I did I could not get a signal out of the sensor. The Dakota Digital unit never gave a flashing green showing that it had a sensor signal. I have been running 5V to the sensor. I read a few posts on other sites that said the sensor needed 8V.

Anyone out there who has done this transfer case swap had an luck getting a speedometer signal? Please post up on how you did it. Sensor voltage, ground, signal wire information would be greatly appreciated.

John

 

[souske]

I used the speed sensor on the 8.8 to run the SGI5, not sure if this helps you any

 

[nosigma]

I used the speed sensor on the 8.8 to run the SGI5, not sure if this helps you any

I am thinking about wiring one up (magnetic pick up) on the rear axle drive flange.

Where did you put the 8.8 speed sensor, and if magnetic, how many teeth?

John

 

[Stickflipper]

Old thread but this may help someone...
I put a 241OR in my 91 Comanche.
I had no speedo.
#1 I had a check engine light (emissions).
#2 The engine kept dying on deceleration (no distance traveled info to ECM).

Some late 90, all of 91 and some 92 XJ/MJs use a reed switch to provide a pulse signal to the ECM which in turn then drives the speedometer.

I tried the Dakota box, the comanche sat on jackstands for two weeks while I fiddled with it. I never could get it to work.

So back to the beginning, reed switch creating a pulsing to the ECM.

Googled reed switch, I was looking for one encased in a threaded bolt design. The reed switch PLUS three magnetic bolts, I ordered from a motorcycle supply house in England. I bought a 3" diameter slug of 6016 T6, locally.
I basically built a tone ring with the aluminum and three magnetic bolts. I was able to press this onto the output yoke. I built and attached a bracket to mount the reed switch.

It simply works, the speedo is not accurate but there is no check engine light and the fuel schedule works on deceleration. I stuck an old gps to the windshield for the times I want an accurate speed. I suppose it would be possible to run some kind of conditioner and make the speedo accurate, but the MJ spends 80% of it's life offroad, it's not worth messing with.