What is the procedure for hooking one up... i have one but dont want to jack anything up in the process today when i do my valves for the first time....

It is pretty simple. You just need one lead to the solenoid on the starter (small terminal) and the other lead with 12V. This can be done either at the large terminal on the starter or at the battery.

Depending upon which model you have you may have a junction box and could hook the starter switch up there as well.

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2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD

It would help to know what vehicle you have.
The turbocharger 123s have a Wire Terminal/Junction Block in front of the Battery on the Passanger Side (US Modes).

One of the Other Chassis has the Wire Terminal/Junction Block under the Battery Tray.

Or, you can get down there under the Car and do as the other Member suggested and hook it direct to the Starter Solenoid.

First pic is listed as Terminal Block SD
The 2nd pic is the Turbo 123 chassis. 2 to the Left are both +; the White Wire to the Far Right is attached to the Solenoid; The Violet (Purple Wire goes to the Glow Plug Relay)

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84 300D, 82 Volvo 244Gl Diesel

On my car I use these.

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1983 300SD
200000miles

Yes, what car?

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83 SD

84 CD

its an 81 300sd.. i jumped the one on the picure and worked good... thanks...