Hi Mark

You might find it easier to do the wiggle/ohms check as follows:

The CAN BUS High and Low should be wired to pins 14 and 6 of the diagnostic socket.
If you get a pre-wired diagnostic plug, something similar to one in the link, you could connect your meter to the wires that are connected to 14 and 6 of the plug with croc clips, make sure none of the wires from the plug are shorted. Plug this into the diagnostic socket, make sure the ignition is off, keys out and check the zero volts on the multimeter. Then switch the meter to ohms, it should show your 66 ohms and that leaves both hands free to wiggle all the CAN BUS connections.

https://www.amazon.co.uk/CERRXIAN-C...2281435176698&psc=1&gad_source=1

Regards Tony