My 86 t/a has an electric speedo that is not working.
When I first put it on the road it worked for a day or 2. I went down a bumpy road and it stopped working. Once it a while if I hit a bump it starts working for a second or 2.
So far I have taken out the cluster and cleaned the contacts and tightened all the contact screws on the ribbon board. I also unplugged the connector on the speed sensor and cleaned that with contact cleaner and plugged it back in. Also checked the connection on the buffer module and that seems fine.
Looking for advice on tests and trouble shooting to narrow down my problem.
I know if could be many things and just looking for how to test the various components like the speed sensor, buffer module, and speedo head.

Thanks!

 

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Anyone at least have a wiring schematic or a link to one?

 

Your car has been converted from a speedometer cable ?

 

No, 86 T/A had factory electric speedo. First year to have them I believe.

 

huh, never knew that. You might look for a fsm on ebay. If you have a scanner or USB to aldl you can view the signal to to the ecm if if from the buffer if this is fuel injected. The digital dash birds had a issue with the ip ribbon seperating.

 

I have a used factory service manual on order from ebay.
It will probably take a week to get here so if anyone has a wiring schematic in the meantime I would really appreciate it!

 

 

Thanks!
That is just what I was looking for!