Velvet Drive temp switch

Hi everyone, first post, long time lurker. This board is a wealth of information but my question I have not seen yet, I hope some one may have an answer. I need to replace the heat alarm sender on my 72 Velvet Drive 1.91 due to corrosion. I discovered this during replacement of the exhaust manifolds,risers and elbows during which I have further decided to completly clean and paint the engines and transmissions. By the way I have been following the elbow and riser thread and have been using it as a guide for this project.

I have discovered there are two choices, Borgwarner #1000-140-004 rated - 190F degrees or Borgwarner #87-88031 rated - 230F degrees.

The engines and transmisions are both original 1984 Crusader 270 with Velvet Drive 72 1.91 . If I had to guess I would go with the 190 but I'm not entirely sure.

Thanks in advance.
R Miller
Sea Esta34C

230 is too hot. The BW manual calls for ATF fluid replacement whenever the temp exceeds 190. This runs normally in the 160 deg range.

This is not to be confused with the neutral switch, which I find last about 8 to 10 years.

PS. welcome to the forums!

Thank you very much for th eresponse and welcome, I should have researched this furter prior to posting. I found a BW instalation manual online through this forum and it lists normal operating temps between 140F - minumum and 190F maximum (not exceeding 190F extended operation WOT). Now I know and I'll order the part.

Rick M.
Sea Esta34C

Actually the 87- is a MERCRUSIER part number, not a BW number.

BW provides two switch options, both at 190 deg F. the difference is one uses the switch case for ground and the other provides both sides of the switch contacts.

AFT flashes at 175, I wouldn't be down there when it hits 230.

Maybe Centigrade; no way it flashes at 175 deg F.

i read close to 400 deg F for ATF. But, i'm sure it "fails to lube" well below that number.

Yes, it is C, about 400 F.