kibbleking

Hi everyone,
I'm doing an engine swap on my 93 4X4 pickup. It had a 3VZ-E in it. I'm replacing that
with a 2L-T Turbo Diesel. I have threads over in Diesel swaps that I also need help with so
if your in the Know on the 2L-T please stop by. But for this forum its a question on how do I
wire up the speedometer without the ECM. I took it out. I found the three wires coming up from the
speed sensor to the front of the truck. I found the same color(s) of wires in the big loom that goes through
the firewall and ends up where the ECM was. The three wires were black/orange stripe that I'm guessing is the
hot or powered wire, a green/blue that i'm guessing is the signal and a Green/Red that may be the ground.
On another forum I read where the signal travels from the sensor to the speedo then to the ECM. ???
So I hooked the wires together. Using a battery charger for power i jacked up one rear wheel.
Give it several spins and no speedo. I've studied the wiring diagrams and just don't know
where I'm missing it. I tried grounding the green/red to good ground source.
I suspect their is power to the gauges as the volt meter pops right up with the key on.

Any Ideas on this ??

Thanks

Clancy

scope103

On my '94, the wires to the VSS1 sensor are
blk/grn: 12v,
green: ground,
grn/red: signal

I never tried to trace it as far as the speedometer. I can't help you there.

RBX

Just a suggestion...
Ignore the wire color and look at the Pin number on the connector and wire schematic, then connect appropriately.

Try:
Pin 1 12v power
Pin 2 Ground
Pin 3 is signal(should connect to VSS on speedo)

Toyota has been using the same wiring for the speed sensor for many years. Also, IIRC, the speed sensor uses a 4-pulse signal that the VSS translates into something the cluster can understand to display speed....meaning you may need to spin the tires for a bit before the speed on the cluster is recognized.

Alss, put a link to your diesel swap in your signature so we can find your swap thread easily.

good luck

kibbleking

Thanks Scope, Your truck is just a year newer. Those wire colors your talking about did you find them where they
plug into the sensor at the tail of the transfer case ?


Thanks RBX,
That seems like a good plan. I'll give that a try.
I'm having a Noobie moment... What and where is the VSS thing.

Clancy

Yet another Noobie Moment...
how is the link thing done ?

RBX

Link...
Go into your user profile settings and add a URL of your swap to the signature area, there should be information on this forum somewhere...probably new user area?

VSS... Vehicle Speed Sensor, usually found inside the speedo, you will simply connect wires to the speedo connector at the appropriate Pin#, this is why you will need a wire schematic for the vehicle.

scope103

I suspect kibbleking has the electronic speedometer, not the cable speedometer. With the cable speedometer, there is a reed switch built into the combination meter to generate the speed signal. With the electronic speedometer, there is a device bolted to the back of the transfer case, with a pickup-gear. Inside the device is a hall-effect chip to sense the rotation of the gear.

There is also a VSS2, which is in the transmission. Since you have a 2-speed transfer case, measuring the speed of transmission does not translate to MPH.

My wire colors are for the harness connection to VSS1. RBX's suggestion is a good one; while the wire colors are usually (?) the same, the pinouts may be more instructive.

kibbleking

Thanks RBX... now I know what VSS is... And I'll work on getting the link..

Scope, Thank you.. Despite the wire colors that drawing above is Exactly what I found.. I may have the ground and signal backwards..
Headed out to test ...
Thanks

Clancy

Heres the diagram I have been using...

scope103

First, check the wire colors on YOUR truck. If they match your wiring diagram, yours is just different from mine. Given that your EWD has black-orange going to JB1, that's almost certainly 12v. Maybe continuously (w/o regard to key pos'n).

Then I'd stick a multimeter on the corresponding pin to confirm that you have 12v to ground. Whichever one of the other two is ground will have 0v to ground, and I don't know what the sense wire would have (harness side). One thing to try is to remove the sensor, put 12v and ground (battery charger is probably closer to 15v, but that should still be okay) on the pins you think are right, then measure the voltage on the third pin. It should vary between 0v and something else (12v? 5v?) abruptly as you turn the little gear. Then you'll know which is the signal line.

What I still can't help you with is whether the ECU has anything to do with the speedometer. My guess is no; there should be a connection for the signal wire right to the combination meter. (My EWD won't help; it's for a truck with a cable speedometer.) If you don't connect VSS1 to the ECU, you will lose cruise control. If you have an automatic transmission, that signal should come from VSS2.

kibbleking

Scope,
Copy on the ECU.. I don't think the ECU has anything to do with the speedo working. As for the cruise.. I removed all that stuff..
As much as I don't want to....I'm likely going to end up pulling the dash apart to get at the wiring to see whats going on...

Thanks for your help..

Clancy