1985 380SL Fast Idle

I have an 85-380SL with only 78,000 miles on it. It only gets about 200 miles per year put on it. In the fall, the last time I drove it, it ran fine. I just tried to start it and the battery was dead. I jumped it to
start it, and now it idles at 1500 RPM.
I checked the idle control valve, and it appears to be working fine. It won't pass air when voltage is applied to it. I suspect that the Idle speed control module may be the problem, but I have no idea where it's located.
I have 2 questions, could the battery being dead for an extended period of time cause a problem with the idle. Can anyone tell me where the idle speed control module is located.
Thanks
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I just ran across this problem... you got a vacuum leak... check all your vacuum hoses for tightness.
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First check the temp sensor, the idle control motor operates based on its input, its about a $10 part. Then replace the Idle Speed Control Mod which is under the pass side dash, It's about a $600 part When in doubt, take it to a Benz mechanic to prove th problem first.
Good luck
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You can get the idle speed control unit from a salvage yard (www.pgauto.com is one of the best for Benz, I'm local to them so I just drive up) for about $150 instead of 600. Richard
wrote:

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Look at:
http://www.slack.net/~thundt/mercedes/high_idle_hell.htm
I resoldered the idle control board on a '81 380 SL per these instructions and it worked fine. Also, there is a reference to a rebuilder of Mercedes analog control boards which are a real problem in older MBs. These include cruise control, idle control. and climate control systems.
The idle control is up above the passenger's left foot, above some cardboard. Bit of a bear to get to, but not as bad as some other things. Its an aluminum rectangular can, IFRC held by one 10 mm nut.
The long term solution is to buy a Toyota, but you probably already knew that.
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Correction - it is a black rectangular can.
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