Speedo intermittent and computer not getting input

I have been struggling with an intermittent speedo and the computer not getting an input.
The symptoms I get is the speedo starts to work after a mile or so stays working for maybe 30 miles or so then stops. The computer was getting mileage reading for a while and hasn’t been getting fuel readings. It now gets no reading so all I getting is a flashing fuel gauge. I have checked and cleaned all the connectors from the engine bay to the instruments and seem to check ok. Ie continuity. It may be that a connector has a dodgy connector, but which one. Or a dry joint? Any thoughts on others experience with this on where to focus my attention.

I had some similar problems and it was the connection from the coil into the connector in the box in the engine bay (assuming you still have and atmo).

Cheers Lee, I’ve looked at that connector which is connected to the coil block. I had a problem with the power supply to the coil in that connector too. Would continuity check out ok but as soon as load put on it would fail. So I’ve given that one and the 3 pins connectors a clean with fine files and tried to tighten the connectors up. Just putting it all back together as I’ve refinished the dashboard plastic cowling as it was all sticky. Been through all the other connectors too.
We shall see if I’ve fixed it.