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\\\M3
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2,299 Posts
Discussion Starter #1
I've got one of the 5" Autometer Electronic Speedo's right now. I have the output of the VSS connected to the SIG port on the back of the speedo, but I have no wiring from the OUT port of the speedo to the Computer. If it helps, I'm using a stripped donor harness and computer from a 90 LX convertible.

Here's the issue, I can't calibrate the Speedo. I followed the instructions: Gauge goes to Full Sweep, then half sweep when I begin Calibrating, but when I stop and hit the calibrate button again, it just goes back to full sweep instead of 0.

I checked the SIG wire going into the back of the Speedo, and its getting between 1 and 2 volts constantly. This doesn't change as the vehicle startes moving and increases speed.

Any ideas here? Should I be looking at my wiring / VSS or does this sound like a bad gauge? I *think* that the gauge worked back when I was go-karting (uncalibrated) but I'm not sure.

Thanks in advance.

Brendan
 

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FFCobra Fanatic
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601 Posts
The OUT terminal on the Speedo should go to EEC (pin 3). It should be Green/White. Connect it and it will work fine.
 

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\\\M3
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2,299 Posts
Discussion Starter #3
Before I look at the canned "This wire to this wire" What should the VSS out be reading for a voltage? I'm assuming it should vary?

I'm just looking for ideas before I rip out the dash on a completed car.

-Brendan

[ May 15, 2005, 08:01 AM: Message edited by: Brendan ]
 

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FFCobra Fanatic
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601 Posts
Originally posted by Brendan:
Before I look at the canned "This wire to this wire" What should the VSS out be reading for a voltage? I'm assuming it should vary?

-Brendan
I don't know the voltage nor do I need to. I think your over analizing this just a tad. You need to get a wiring schematic and locate pin 3 on the ecu harness and then trace it towards the speedo, cut the wire and splice it onto the speedo.It is like putting an inline fuse in but in this case, the speedo is the fuse. The end that comes from the VSS goes SIG and the end coming from the ECU goes to OUT. The instructions for the speedo CLEARLY state this. Just find that one wire and make the splice and you will be done.
 

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Charter Member
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6,152 Posts
Brenden,

dont rule out that the gauge is broken. When I started the calibration it went straight down instead of full sweep. I had to send it back and they gave me a new one. I cant help with your wiring I have a carb and had to buy the autometer sender that has a single wire that connects to the SIG. I dont have an OUT wire at all.
My speedo still doesnt work. It only starts counting if I dont depress the starter button to crank the motor. If I start the calibrate sequence and roll down a hill it will start counting. If I fire the engine the calibration button doesnt do anything. Now that's a FREAKIN problem!
trevor
 

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Senior Charter Member
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123 Posts
I went throught this with my Autometer speedo. Autometer told me that the "out" wire on the back of the speedo can't be connected to the computer, something about square vs. sine wave signals. I also couldn't get my speedo to calibrate using the Ford VSS. The solution was to use the Autometer VSS with 3 wires connected straight to the speedo, and no VSS signal to the computer. Fortunately my computer/engine combo is not one of the ones that needs a VSS signal to the computer in order to run right.
 
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