I'll be replacing the tailgate wiring harnesses shortly. Just making sure I have the materials. The "Volvo Problem Solver" says to make sure the bolt and wire harness holes are properly caulked. OK, what caulk? Silicon? Permatex? Thanks.

 

I did the tailgate hinge replacement/wiring harness bit myself a while ago. When my 16 y/o son and I took off the hinges , the "caulk" that was there looked just like plumber's putty that had hardened a bit over the years. So that's just what we used, plumber's putty that you can get at any home store. So far, no leaks, corrosion or paint damage. RTV Silicone would be my next choice, but the putty also worked well in holding the washers/spacers in place that need to be held in alignment to replace the bolts.

 

You can use windscreen sealer (not windscreen adhesive) for this. It never truly sets so remains flexible and is easy to clean up.

Regards, Andrew.