Can anyone explain exactly what works off of what on a stock 87 GN? From what I have seached for and read here. The speedo is driven off of a gear system from the transmission and the trans has a VSS (Vehicle speed sensor) that sends the pulse to the ECM for converter lock-up, etc. This VSS signal is what is read through the ALDL port from a scanmaster.
My questions are:
1. Is the VSS sensor inline in the speedo cable under the hood? The reason I ask is mine has a brass "T" coupler where the two halves of the speedo cable come together and have wires coming out of the other end. I could not figure out what this is.
2. My odometer stopped working as well as my trip meter, but my speedo remains to function. I am guessing this is something mechanical within the gauge?
A little background on the car before answers. The car was originally a Canadian car that had the dash swapped out with a VDO "GNX style" dash somewhere in the early 2000's. I purchased the car with the VDO dash in place. The speedo, odo, and trip meter were all functioning when I purchased the car this past March. in the last week or so the odo and trip meter died. So my first priority is to get them back up and running. Secondly the speedo never seemed to have the correct speed. It would say 50 when my GPS would say about 62-65 mph. The VSS speed would say about 55-60 at the same GPS speed. I am guessing that the dash conversion was performed without changing gear from metric to standard because it was a canadian car and that is probably the root of the speedo calibration problem.
Please forgive my ignorance in this matter, this is my first auto trans vehicle in 20 years.
So...what do you guys think?
My questions are:
1. Is the VSS sensor inline in the speedo cable under the hood? The reason I ask is mine has a brass "T" coupler where the two halves of the speedo cable come together and have wires coming out of the other end. I could not figure out what this is.
2. My odometer stopped working as well as my trip meter, but my speedo remains to function. I am guessing this is something mechanical within the gauge?
A little background on the car before answers. The car was originally a Canadian car that had the dash swapped out with a VDO "GNX style" dash somewhere in the early 2000's. I purchased the car with the VDO dash in place. The speedo, odo, and trip meter were all functioning when I purchased the car this past March. in the last week or so the odo and trip meter died. So my first priority is to get them back up and running. Secondly the speedo never seemed to have the correct speed. It would say 50 when my GPS would say about 62-65 mph. The VSS speed would say about 55-60 at the same GPS speed. I am guessing that the dash conversion was performed without changing gear from metric to standard because it was a canadian car and that is probably the root of the speedo calibration problem.
Please forgive my ignorance in this matter, this is my first auto trans vehicle in 20 years.
So...what do you guys think?
