LS swap Speedo sender type...

[bs46488]

Hello,

Looking for a little help on the wiring for my LS swap.

I purchased an electric speedometer from Speedway Motors and having a little trouble determining which type of sender is coming from the LS? If it matters I installed a 5.3 with a T56

The three options for the speedo can accept are as follows:

3-wire Hall effect sender with output 3 to 15 V
2-wire magnetic sender with 1.2 VAC min
5V square wave (cmos)

Then they give the wiring options as follows:

Yellow wire to magnet sender
Blue to magnetic sender
Green to hall effect sender

Any idea of what type/color wire I should hook the VSS up to on this speedo harness?

Thanks,
Brian

[LS short box]

It kind of depends on how your LS harness is configured. With a T56 you can wire the VSS directly to the speedo not thru the ECM. I've only used Autometer speedos on my LS swaps. They have a spade connector on the back you can plug the one wire directly from the VSS. The other wire from the VSS goes to ground.
Or if your harness has wires running directly to the VSS and then to the ECM you need a "speedo" wire in the harness to connect to the speedo. Most tuners like to have a VSS signal thru the ECM because it allows them to fine tune the tune with a VSS signal.
Again I'm not familiar with the Speedway gauges but for sure Speedway doesn't make it and it would be nice to know the suppliers and contact them for details.

[dayj1]

Originally Posted by bs46488

Any idea of what type/color wire I should hook the VSS up to on this speedo harness?

Based on the phrasing of your question, you want to wire the VSS sensor directly to the speedometer?

If so, the VSS is a 2 wire magnetic sender.

So, according to your description:

Originally Posted by bs46488

Yellow wire to magnet sender
Blue to magnetic sender
Green to hall effect sender

That would be the yellow wire and the blue wire to the VSS sender.

The previous reply is also correct about multiple ways to connect the speedometer. If it were mine, I'd prefer to wire the trans VSS output to the PCM and then the PCM will have a speedometer output. That'll be a square wave signal and would go to the green wire on your speedometer.

[bs46488]

Just wanted to provide a little more follow up.

I originally wired the VSS from the trans to the PCM, then I'm using the VSS from the PCM to the speedo.

I called Speedway, they didn't know anything. The tech guy wanted me to get a speed reference from the wheel sensor. So that was a lost cause.

So the gauge is wired to the green wire. I fired the car up in my garage and it reads that I'm going between 120 - 140MPH....while I'm sitting in the garage at idle in neutral.

Not sure what is going on. Here were my thoughts...

1) I haven't calibrated the speedo yet and it doesn't know what's going on.
2) Its a cheap speedo (because it was cheap!) and can't process the signal.
3) Bad VSS on the trans (I bought a used core and had a trans guy rebuild it)

[LS short box]

Sounds like its similar to Auto Meter. They read fast until calibrated. Just watch how fast the odometer spins. Try the calibration before changing any parts.