Rebob5

iTrader: (3)

For my SBC swap I went with aftermarket gauges and everything is working fine except for the speedometer, It doesn't want to cooperate HAHA. I did a bunch of searching on the t-56 vss (vehicle speed sensor) and still have no luck. Originally I had the tach wired as it shows in the instructions, yellow wire to yellow wire and blue wire to purple wire on the vss and as soon as the car starts up the gauge just bounces all over the place. I read on another thread that one of the wires (doesn't matter which one) on the vss need to be grounded So i removed the purple/blue wire and hooked it to ground as as soon as the motor is running it does the same thing, Just bounces all over the place. Please help me out.... what am I missing??? Thanks

Here are the instructions it came with....

Rebob5

iTrader: (3)

any suggestions? At this point the gps speedo app on my phone is looking like its going to get used when I first get my car out and I will make mental notes for rpm and use that to know if im going the speed limit HAHA

Tolley's94z28

iTrader: (4)

I was having problems like this when I put a 97' t56 in a 93' car. I ended up just switching all the wiring.

Anyway, I remember something about a signal box that changes the vss pulse so that it can be used in applications like yours. The pulse goes from the tranny to, to the pcm, then to the speedo IIRC. The company that makes it is dakota digital. They aren't a sponsor, but maybe everyone will be cool with me suggesting it since it is a specialty product! Start there and see if that is what you're looking for! Good luck!

Rebob5

iTrader: (3)

Tolley's94z28 Thanks for the reply!I dont know if that will work for my application tho, I dont have a PCM in my car anymore. From what I read I should be able to hook the VSS to my new speedometer and it should work that way but it doesn't seem right. I will send a e-mail to the manufacture and see if they have any suggestions.

Tolley's94z28

iTrader: (4)

I was just throwing it out there, since I had some trouble getting info on it. Put up a write up when you figure it out though! Im sure it will help some fellow car nerds in the future! Good luck OP!

stevieturbo

T56 VSS is a 2 wire magnetic pickup, so it should just be those two wires to the yellow and blue of the gauge according to that diagram.

Rebob5

iTrader: (3)

stevieturbo: Thats what I thought, it seems like a pretty straight forward install lol. I did a bunch of research and like you said it should just hookup to the 2 wires and should be good. Its just weird that when the car is not running the speedo is on zero and as soon as it starts the needle on the speedo just bounces all around, I wonder if it is just doing that because i haven't drove a measured mile to program it and it just doesn't know what to do at the moment. Thank you for the help!

Tolley's94z28: Once I get it figured out I will be sure to post it up so it might help someone in the future.