The starter has a male small spade connector. One end of the switch goes there. The other goes to constant 12v. I used the jump start connection point.

Cleaning with the valves closed is the only way to do this job so I am unsure why you are asking if that is acceptable. Do you have the diesel vacuum adapters? I did not blast the plastic areas as they are expensive if damaged. Cleaning the valve cover intake area was by hand was a pain but safe. I dropped the intake off at a machine shop for cleaning. I used walnuts as the build up on the valves is tough to get off. I probably put 20 hours into the job. Don't be fooled by the N54 335i gas videos. Diesel CBU is a lot more work than gas.

You may want to delete the EGR to completely prevent future build up. I did not have a lot of build up at 80k miles and I won't have this vehicle until it happens again.

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2009 35d, 2006 325i & 330i