SLP Speedo Recalibration Box
 

I'm having fits trying to get this mofo to work in our purple T/A and I NEED it working by tomorrow evening (going in for 4.10's).

Does anyone have any experience this these things?? I know for a fact that I've got it wired in correctly, but the problem is that the speedo just dies at 15 MPH and won't come back until I'm below 15 MPH.

Ideas?