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Marty, ASE Certified Technician
Category: Mercedes
Satisfied Customers: 54943
Experience:  Bosch Certified Master Technician with over 35 years experience in the automotive industry.
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I Have a 1992 R129 SL and want to know what controls the cold

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I Have a 1992 R129 SL and want to know what controls the cold relay regulator as it is not working. This only happens on Cold start.
Thanks . Saleem
Hi Saleem, the cold start valve is powered with 12V by the overvoltage protection relay. The valve is grounded by the engine control unit to activate the valve during cold start cranking.Let me know if you need anything else. Please rate my service as this is the only way that I receive credit from the website for helping you.Marty
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Customer: replied 2 years ago.
where is this located as I cant find it. do you have any drawings?
It's right behind the silver relay with the knob on it in the picture below. There is a fuse in the top of the relay.
Customer: replied 2 years ago.
Thanks. I will have a look in the morning and let you know if I've fixed it.Saleem
You're quite welcome.