97 f250 vss wiring question

thetintguy001 · Feb 28, 2016

To start i have a 78 f150 supercab mounted atop a 97 f250 frame, its a project ive been working on it awhile. It runs and drives but ive been dealing with a shifting issue. Some of you might have seen my other post.
But to get to the point i discovered the 2 wires (red/pink) (green/dark blue or black were cut. Im not running the 97 gauge cluster, and id like to know if i can bypass that by hooking the vss wires directly to the pcm.

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thetintguy001 · Feb 28, 2016

I have a evtm on the way, and ive poured over the diagrams ive found online. Maybe someone has been down this road before.
Looks like pin 33 pink/orange is vss - and pin 58 grey/black is vss+

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markfuga · Feb 28, 2016

No, you cannot wire direct to the PCM, the VSS sensor is read by the PSOM which translates the signal for the PCM. It's simple to wire up and the EVTM shows it on page 64-1.

markfuga · Feb 28, 2016

BTW: I'm in the process of the same project, putting a 78 F250 regular cab on a 96 F250 frame. I've been swapping the PSD into older trucks for a couple years now so if you run into any other problems, send me a PM.

You don't need the whole gauge cluster, just the speedometer module and it's wire pig tail from the harness. Just wire it according to the EVTM and then tuck it up under the dash where it's hidden, or mount it in a bezel for display as an alternate speedometer.

thetintguy001 · Feb 28, 2016

I came across this article earlier today, which if im reading it correctly in 97 they changed the (vss) communication to go to the pcm directly. Am i wrong in this assumption?

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markfuga · Feb 29, 2016

It may apply to the F150 which saw changes in 97 and other light duty trucks (Explorer) but not the F250/350. The image I uploaded is from the EVTM for a 97 F250 which clearly shows the VSS going to the PSOM.