I picked up an instrument cluster from a 1989 420 SEL the other day and am thinking about using it in my 1983 300SD, in order to have an OAT temp gauge.

I would simply transfer over the SD instruments into the SEL cluster housing and use the temp display, which is a 4 wire (part number 126 542 02 27).

1. Can I just hook up a thermistor (listed in other threads) to the display, and then ground and 12 volts, or are there more components in the system than just the thermistor and the display?

2. Where do the wires go? (I have the harness that goes into the four wire plug)

* two browns (I assume these go to ground)
* green
* gray/blue
* purple/black