My mechanic says I need a thermo time switch #004-545-91-25. It's NLA and none seem available online. This is a long shot but does anyone have a spare or any leads on one?
Did you try Autodoc
I just did, but no luck there.
Going by the information on your profile, a 1974 450sel would have D-Jetronic fuel injection. If this is the car you're referring to, then the part number you need for the thermo time switch is 003-545-90-24. I'm not sure where you get 004-545-91-25.....it doesn't even come up in EPC, nor is it shown in any of the parts books.
Although used, here are a few places that show to have the part:
http://www.2040-parts.com/mercedes-benz-vdo-new-thermo-time-switch-003-545-90-24-for-engine-m116-m117-i1084619/ (http://www.2040-parts.com/mercedes-benz-vdo-new-thermo-time-switch-003-545-90-24-for-engine-m116-m117-i1084619/)
https://fuelinjectionproducts.com/products/mercedes-thermo-time-switch-0045454924-0035459024-vdo-36-2-17 (https://fuelinjectionproducts.com/products/mercedes-thermo-time-switch-0045454924-0035459024-vdo-36-2-17)
Oops I must have copied the part number down wrong from my mechanic. Thank you!!