On the 4t65e HD on my swap, at the pass side axle housing,(on top), there is a sensor.... Exactly WHAT (Wires/adapter) am I needing to "GET" / "hook up" to this ?
I have wires "waiting to hook up" that say for VSS vehicle speed sensor. I Think someone said that an "adapter" is needed for this. Is there a "Diagram" anywhere? Pictures would be Great. Thanks

quote Originally posted by Lou6t4gto: On the 4t65e HD on my swap, at the pass side axle housing,(on top), there is a sensor.... Exactly WHAT (Wires/adapter) am I needing to "GET" / "hook up" to this ? I have wires "waiting to hook up" that say for VSS vehicle speed sensor. I Think someone said that an "adapter" is needed for this. Is there a "Diagram" anywhere? Pictures would be Great. Thanks

The sensor that is on the passenger's side extension housing on the transmission is the VSS (vehicle speed sensor). This sensor needs to be directly connected to the PCM - no interface module or anything. Just wire it up directly to the PCM.

Now, in order for your Fiero speedometer to display vehicle speed correctly, you will need to build an interface module that installs between the Fiero speedo and the PCM's 4k PPM VSS output. A schematic for this circuit can be seen here:
http://www.gmtuners.com/fiero/speedo2.gif

Or, there might be a vendor or two on this forum that sells pre-made speedo conversion modules.

-ryan

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OVERKILL IS UNDERRATED

Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com

That what I needed to know. I think theres 2 wires for vss and 1 or 2 for 4000 ppm. I'll need to find a" Vendor", making the harness was more than enough for me, diodes and resister are "Beyond my pay scale". been saying I'm going to learn about electricity for 30 years, maybe it's time. Thanks

that circuit is easy to build....you should just build it yourself. And the parts are cheap as well. If you lived close, i'd give them to you. I bought the parts to make one for my swap, and found out after that the harness i buy will have it built in already...so not needed. I think i paid $10 for enough parts to build 2 circuits.

I'm a little confused, I bought my harness from a vendor (Timm / Phonedwags) I just hooked everything up and my speedometer works perfect? I also had the PCM programed by ZZP, I was under the assumption that the Spedo calibration was in the PCM's Tune

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1986 SE 3800SC/4t65eHD (12.871@104.96) I'll Sell it if you like
1985 GT 3800SC (swap in progress)

so, blue #64 to B, and blue #65 to A on the vss Sensor. and #55 blue (4000ppm) to the "interface", 1 wire to pin F of 203, and the other to Pin G of 203 ?
Duh, thanks for the help. be Sooo happy when this is finished.