Simplest Way to Bypass Servo?
 

I want to bypass my broken servo, so I can defrost my windows in the morning, until I can find a suitable replacement. I did this once before by connecting the hose that's highest on the firewall to one of the other hoses using a pipe with shut-off valve in it. However, I can't remember which hose I connected to the other side of the shut off valve to get heat.

Thanks in advance.

here you go

http://www.peachparts.com/shopforum/mercedes-benz-sl-discussion-forum/267993-urgent-w107-bypass-acc-servo.html?highlight=servo

You do understand that, if you bypass your servo, you will loose the vacuum controlled ventilation "flaps" , and have no control over where the airflow emanates from... The top half of the servo directs the vacuum to the respective "pods" to open or close them. The default for the different flaps can be found in the MB service manual. You will want to review, I think...

Advertised on this board is a digital replacement. Kinda pricey, but I have heard reported from one user of satisfactory performance. UTwired, or similar... was a sponsor for a while, and add would come up atop the board...

you can also get a rebuilt "stainless" servo for just under $500

Thanks for the replies. I decided to bypass the coolant flow to the servo by (1) using a reducer to connect the 1/4" hose from the aux water pump and the 5/8" heater hose (2) a 5/8" nipple to connect the other, two, 5/8" hoses that enter and exit the servo nearest the firewall.

Since I left the vacuum lines and electrical connections on the servo, switching from defrost to bi-level slows the blower motor down, but doesn't allow me to control the temperature. However, I can live with that, at least until I decide whether to get a used or rebuilt servo.

I considered getting the digital version, but I can't justify paying an exorbitant price for a system that costs less than, and probably a lot less than, $100 to make, even considering start-up costs.