more 560sl high idle stuff - PeachParts Mercedes-Benz Forum

ddayme · #1 11-27-2009, 10:29 PM

As I mentioned in an earlier thread, I think my problem with high idle is the OVP relay, and as a temp "fix" I wedged a small piece of vacuum hose in it to keep the relay closed= normal idle. Today while checking the oil, I noticed a small humming noise, and it turns out that the idle speed solenoid has current going to it even with the key off/out of the ignition! I'm sure it is because of my forcing the relay "closed", so I guess the OVP relay is powered even with the key off? could this be another sign of what the problem is? I know that keeping the relay closed is not a proper fix/repair. Any thoughts? Anyone have a good used relay? (I am currently cash poor, so $90.00 for a new one is too much right now).

Thanks,

DDaymen

ddayme · #2 11-27-2009, 10:37 PM

Addition to last message: there is a temp switch/sensor that has a 2 wire connector going to it, and when I first got this car, the a/c compressor would not come on unless one of the wires was disconnected from it. Could this also be a possible reason for high idle? causing the OVP relay to "open"? just a thought.
-DDaymen

david s poole · #3 11-28-2009, 11:59 AM

the ovp relay has a terminal #30 which is battery power all the time in mercedes language.the temp sensor you are referring to produces a ground signal [when too hot] to shut down the a/c relay.

ddayme · #4 11-28-2009, 11:46 PM

okay, thanks for the reply!