Test VW Jetta TDi glow plugs and harness

Welcome to my messy garage, where there is always a project going on...

This is how I tested my glow plugs and wiring harness. This isn't some offcial way, so you might want to double check for yourself if this is a good way to test. I'm happy with the results. On the last part, you should check the Voltage to all 4 glow plugs. I did this testing just to put it on Youtube. I already checked them all.

I had a bad glow plug I changed last week and the trouble light went off for a little while than came back. I think the problem I had after changing the bad glow plug is I didn't snap in the harness to one of the glow plugs very well. After this I also cleared the trouble codes. No more check engine light, but I'll see what happens when I drive it to work tomorrow.