Another glow plug circuit issue

[C_Luft]

As the title says I have an issue with my glow plug circuit, my glow plugs are new(motorcraft) as of Sunday. I an still getting a lot of clicking after 2-3 seconds of wts light (and hard start at 45°). My harness is in (visually) good shape I only needed to re do one bullet connector on Sunday. My relay and controller are old, but I do have a spare.

After looking online and on here I'm not really clear on how to test the resistance on the controller, glow plug wiring ect. Maybe we could start a sticky for testing glow plug circuit, all I found was how to install a push button switch.