OBD gremlins ... need assistance please

[HSRACER]

So I bought a 67 with a 5.3 in it already and the PO had the OBD port laying under the hood.

While it was in that location I had my tuner come give the engine a once over and cleaned up some parameters in the computer. At the time I didn’t have ac in the truck or a working speedometer.

I have since added Dakota Digital gauges and old auto air to the truck. While doing some work to it I also thought I should have the obd port under the dash as they were from the factory.

Here is where the problems start. I extended the data wire (purple) and the power is hooked to a constant hot. The two grounds were attached together and screwed into the kick panel on the side under the dash.

My buddy has done this setup many times in his LS swaps without a problem.

I need to get into the computer again to turn on my fan trigger for the new electric fans I have now installed and the computer is not recognizing my hp tuner hook up or a small scanner code clearer that I have.

I have pinned out the data line and ensured continuity from the connector to the obd tab. My friend butt connected them and heat shrinked as well.

Another friend told me you can’t butt connect the data line as it is to sensitive to resistance so I then removed the connectors and soldered the wires.

Still no luck on the ability to get the computer to talk with either of my scanning devices.

I have read that some people have had to extend the two ground wires back from the actual harness vs just grounding them together on the body.

I will be unwrapping the main harness tomorrow and looking for those two ground wires he cut and seeing if extending them to the obd does anything different.

Also the Dakota Digital Gauges aren’t seeing a speedometer output. Wonder if the issues are related?

Any additional thoughts or advice is greatly appreciated!