Ive done some extensive searching and have yet to find the answer to my specific situation

I swapped a speed density tpi into my 89 using a SD engine harness/ headlight harness and I did a full dash swap with interior harness, the only thing not working right now is the speedo, the dash was from a v6 91 camaro and I've seen different info about the buffer box. Some threads pocket says to cut it and rewire the c207 others say to put one in. Any info on this? I don't have a buffer box in there that I've seen so is it possible for me to take the speedo wire and just tag the Vss output? I believe its B11 at the ecm, correct me if I'm wrong

I bought the proper Vss, put my old gear on it and used the engine harness connections to wire it up yellow/purple.


Any info would be appreciated

 

The 730 ecm has a buffer in the ecm. B9 will be your vss ground purple wire form the vss, B10 is the vss input yellow wire from the vss and the output to your speedometer is B11.

 

Your old TBI system used the buffer box, but the new TPI speedo does not use it. Basically you just need to bypass the buffer box. These wiring diagrams help on stuff like this. http://www.austinthirdgen.org/index.php?pid=19 Or just listen to tunedperformanc. He beat me to it.

 

There's nothing tbi in the vehicle, I used a v6 91 harness, so would my option be to take the speedometer wire and run it to b11? Idk why it isn't working already but I would like to get this hashed out for obvious reasons

 

90-92 TPI and V6 dash harnesses are nearly identical. You wont have to bypass anything when using them together

Grab a meter and see if the VSS circuit is functional, then with the C207 plugged up, test the ECM to clutster circuit

 

What would I be lookin for? Voltage or ohms? And could I cut to the chase by hooking up my laptop to the aldl to find a signal? I am pretty positive he Vss is functional as I haven't thrown a code for it, ice been told the 90's clusters are prone to failure any truth to that?

 

https://www.thirdgen.org/forums/elec...t-working.html

 

Ohms

OBDI systems will not tell when something like the speedo is inop. If the VSS is not sending a signal or blatantly wrong signals it usually will though

90-92 clusters went fully electric and have some common issues, mostly with the tach

 

Well I went for a spin today and found there is no Vss output to the ecm, the ecm showed 0 mph, and then shortly after I threw a code 24 for the first time, I think the gear may not be sitting on the Vss like it should, its a 4000ppm BWD sensor I just bought a week ago, so I'm leaving more towards the gear not meshig up, I was thinking of hooking up the aldl, then attempting to spin the Vss to see if it has output, that would tell me the wiring is good, I clipped the connector from a v6 engine harness, is it possible the wire colors are different on v6 and tpi? I know the connector is keyed and can only go one way I just want things to keep an eye out for before I dive in, I like having multiple troubleshooting options