It may be difficult for you to retrofit it into the 300TE unless you know relay and auto electric well. This is what I suspect has been done on the 260E.

1) The 'odd blue' wire is tapped off the compressor harness. It is energized with 12V whenever the compressor is turned on.

2) The 'odd blue' wire is fed into the relay pin 86, 85 to chassis ground to turn on the relay to 'jump' the high pressure switch.

3) pin 30 is tied to the one side of the high pressure switch, pin 87 is the other side.

Others can chime in. Good luck.

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.