speedo wiring?????

[speedvisioncavalier]

when i swapped my quad 4 into the cavalier, i never got around to actually hooking up the right wires to make the speedometer work. (i just wanted to get it running for the bash, and i was skipping things that werent essential). my dad worked mostly on the wiring, but couldnt figure it out.

which wires on a 1991 beretta GTZ wiring harness are the ones that control the speedo? i would assume there is a wire fromt he tranny that goes into the ECM, and then there would be an ouput wire that goes to the gauge itself. do you think GM would have changed anything so that my cavalier gauge wouldnt accept the signal from the beretta ECM? im using the GTZ wiring harness under the hood and its ECM, but i spliced most of the interior stuff back to cavalier so i didnt rip apart the dash, and i could keep the cavalier gauges etc.

what do you guys think?

[cavfan1]

Uh, what kind of VSS did the GTZ have? Was it a cable, or a magnetic pickup type? Same question for the cav, which one did it have? I would think that if both cars had the same style VSS, you could get it to work again. If they aren't the same type, you might be in trouble.

Not knowing exactly how the computer reads a signal from a MP type VSS, I would say that the ECM has the FDR in the prom, and makes an output to the cluster based on the pulses of course. So long as the trany Ratio and the prom ratio match, the cluster would read correctly if wired right. Ill have to check on the computer at work tomarrow, but i can get the wiring diagrams and scan them for you. Basicaly, you would take the wires from the VSS and route them to the right pins on the ECM connector, then take the outputs from the ECM and stick them to the right ones on the cluster.

As for the cable opperated speedos, all you would need is the cable, and hope the ends plug into the VSS and the cluster correctly. Then hope the speedo is calibrated properly to the FDR in the trans. I think thats how they do it. ;)

[DominionTuner]

Just replace it all with Autometer guages ;)