....and, if you really need it to be waterproof, cover the solder joint with RTV right before you slide the shrink tube in place. Then heat the tubing from the center out. The RTV fills the gaps, pushing the air out. Wipe off excess RTV extruded out each end of heat shrink.

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'82 300SD - 361K mi - "Blue"

"Good judgement comes from experience. Experience comes from bad judgement."

listen, look, .........and duck.

Yes, you can certainly make a case for the heat shrink tubing.

But, if you are not going to replace the entire wire and simply need to strengthen the existing insulation where it has cracked in several places, then the electrical tape will do a fine job. I rather like the strength of a properly done job with electrical tape. The heat shrink tubing never gives me a good feeling about protecting the splice from a strength standpoint. The tape provides good strength in a hostile environment (the operator moving the wires around at every opportunity. )

We'll see how it stands up to the heat. I do have some concern about the heat causing it to peel away from the wire.

Oh my, this sounds like it will turn out to be quite a project for me. If i don't get to it for a while (a few days), do you think it would be a problem to drive with it as is?

Also, when I go to take this bad wire out ... how the heck do I remove the top connection of it? Obviously the bottom part comes right off of the sendor above the t-stat, but the top portion disappears into a "bundle" of wires and I'm not sure where it ends up. I have wiring diagrams but they're not exactly arranged in a manner that translates well to the actual locations of things in the engine.

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1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)

C, just tape the wire where it's bare so it does not contact any ground. Take you five minutes.

If you decide to do the complete job with heat shrink tubing and a new wire, one end of the wire will attach to the sending unit. The other end of the wire needs to be soldered to the wire that comes out of the "bundle". You'll need to cut the wire, close to the bundle (three inches away) and then solder the new wire to the existing wire that comes out of the bundle. If you use the heat shrink tubing, make sure you put the tubing on the wire and slide it down out of the way, before you solder it.

What, doesn't anybody dip their stuff in molten rubber anymore?