WUR at 10.5 ohms?

[Barenecessity]

I took out my WUR and unhooked all of its connections. I then tested the contacts points with a multimeter set on ohms. First the meter read between 9 and 10 ohms. When I reversed the test leads the meter read 10.5 but sometimes up to 13. Are these readings adequate? I know the ideal readings should be 30 ohms. . .

[boyt911sc]

Originally Posted by Barenecessity

I took out my WUR and unhooked all of its connections. I then tested the contacts points with a multimeter set on ohms. First the meter read between 9 and 10 ohms. When I reversed the test leads the meter read 10.5 but sometimes up to 13. Are these readings adequate? I know the ideal readings should be 30 ohms. . .

Bare,

I have a half dozen bad WUR's (0-438-140-090) that register between 9 & 10 Ohms. I don't know why they seem to fall at this range when they go bad. They seem to be very consistent ( bad -090 WUR's) to register at these values. So what's your WUR? Keep us posted.

Tony

[Barenecessity]

Thanks BT, mine is a 090 as well. Does taking it apart and cleaning it do anything or do I have to get a new one?

[1982911SCTarga]

Is the 090 the type that's got those leaf switches inside it?

Brian

[1982911SCTarga]

My description of an 090 from another thread:

Originally Posted by 1982911SCTarga

My late-model SCs use a later-type "090" warm-up regulator, or control pressure regulator, that is equipped with an internal leaf-switching device (I think some Mercedes used these as well). This leaf switch has an adjusting screw, but for the life of me, I can't figure out how it functions, other than introduce another current path to heat up the bimettalic strip. This leads me to think that it's got something to do with the pace that the bimettalic strip heats up. I've poked around checking ohms resistance at various points with my multimeter and haven't learned anything conclusive.

Has anyone figured out (Tony?) how this switch functions and how it can be adjusted? Thoughts?

Brian