I changed the thermostat last night on my jeep and the old one had this little bypass thing but the new one I got from Part Source didn't have it. What's it do and do I need it? (this isn't my t-stat, but it shows the bypass i'm talking about)
Nope, fail safe is a 1 way clamp thing that it opens into and clamps it on the sides. Not exactly sure what this little bypass does.