Speedo not working

[tweeder]

I looked into the speedo and vss but am still confused as to where to start? A previous owner did. 3800 swap with a 866 4l80 CFD 910 hydra-matic(not sure what that is or where it's from). My tac works but no speedo or odo.

[falcon_ca]

Do you know if the PO installed any converter ?

[Dan]

Needs a speedo buffer circuit to work, very easy to make your self. Dan

[tweeder]

Do you know if the PO installed any converter ?

Unsure but unlikely.

[tweeder]

Needs a speedo buffer circuit to work, very easy to make your self. Dan

Care to elaborate more?  I searched "speedo buffer circuit" but only came up with 3 other hits.  Not sure if any apply to me.

[aaron88]

If you don't know how to or don't want to you can buy one.  Here is one that a few people are using.

I chose to make one BTW.

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