VSS wiring

[Turbo F-bird]

I'm a little stumped on the wiring for the VSS in my hybrid Cutlass wagon. I have the Casper's harness and a new VSS buffer but I get no mph readout on my Scanmaster and a code 24.

I re-checked the wiring and I have the brown/black wire from the ECM going to the brown feed wire of the buffer Just like the Casper's instructions say. I have power at the pink/black wire but I don't have a ground at the black wire which goes to the P/N switch no matter what position the shifter is in. This is going by the wiring according to the Olds wiring manual. I was going to go further with the P/N switch to figure out why I have no ground and I figured I'd look at the Buick manual for the heck of it.

The Buick manual shows 12 volts coming from the ECM on circuit 437 going to the buffer which makes no sense to me nor do I have any power on that circuit. I thought the ECM only grounded circuits and had a maximum of 5 volts on them?

So how is everyone wiring their VSS? What am I doing wrong here? I'm a little confused to say the least.

 

[mikestertwo]

The black wire on the buffer goes straight to ground, it doesn't go through the P/N switch.

 

[Turbo F-bird]

I was going to put it straight to ground but saw in the Olds manual it went to the P/N switch so I figured the ECM used it to figure out if it was in gear or not. Then I saw the Buick wiring was different than the Olds wiring so I thought it wise to stop and put out a request for advice from you guys. If I put the black to ground and the problem is solved I'll erect a statue to you in my yard

If I have power, ground and the ECM feed to the buffer as long as the mirror in the speedo is OK it's got to work right?

 

[mikestertwo]

As long as the sensor is good in the speedo and the buffer is good it should work. :smile:

 

[Turbo F-bird]

I'll find out soon enough. Thanks for your help!