Okay, the '87 GTA 350 started as an auto from the factory. Along the way, it was given a 5 speed trans out of an '85 T/A. For some reason, the speedometer does not work. The car runs, shifts and idles like a dream, but the speedometer does not register that the car is moving. All other guages work fine, just the speedo is not working. Anybody have any insight as to how I could fix this?

 

I had a similar problem, but with the auto trans. How is your vass connected? It should have a yellow and purple wire from the VSS on the trans to the yellow buffer box under the dash passenger side.

 

I don't remember the color wire that connects to #15 on connector 2 that the instrument cluster connects too, but it's for the input of the speedometer from the yellow buffer box. On connector 1 the "G" plug is for the ground side of the speedometer from the buffer box also.

 

I'm a Camaro kinda guy, so take the following with a grain of salt: Your 87 would have originally had an electronic speedo, the 85 a mechanical. You need to snake under the car and see what's what. To make the speedo work, you need a VSS in the tail shaft of the trans.

JamesC

 

It's not a digital dash.. Car is a factory L98, heavily modded and trans swapped, but I can't figure out why it's not registering. I really would rather not take it to a shop, but I'm out of ideas!

 

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was your speedo cable driven?

 

Digital and electric are different bears. Your speedo is electric.

JamesC