Hi Guys,
So I'm replacing pretty much my whole cooling system today because it's just plain nasty. The guy I bought the Bronco from ran straight water in it for a long time and it has a lot of rust everywhere. The radiator leaks too and as cheap as parts are, what the hell, buy all new and have a great running older truck. So my question is about the ported vacuum switch that mounts in the thermostat housing. It is a 3 port yellow switch. I don't know if it's bad, but figure as bad as it looked when I took the housing off, I should replace it too. Autozone shows the switch as being brown, but O'Reilly's has brown and yellow. What the truck has in it right now is a Ford stamped OE part and it is yellow. Does anyone know what the difference is and if it matters which one I put in? O'reilly's is more expensive. Thanks for the help! Go KSU, beat OU!

 

The best recommendation on an electronic component like this is to go with the OEM replacement. Yes, its going to be more expensive than the aftermarket at a parts retailer but you will be getting the right part if you go directly to Ford to get it. The switch is thermally activated and differences in thermal tolerances in aftermarket parts could cause you more headaches down the road.

 

Thanks Greystreak92. So is the difference in color the temperature in which it opens the switch? For example yellow opens at 192 and brown may not open until it hits 195?

 

Most likely yes. As with any thermal-electric device, the actual temperature at which each one opens/closes will vary slightly from unit to unit even with two presumably identical devices. And a new unit will be different from an old one. Its the nature of the devices. The resistance is affected by innumerable factors so getting as close as possible to what the system was designed to operate is the best way to ensure that it keep running properly.

 

Thanks for the education!