I have a 1990 240DL - This weekend I found an '81 Turbo in the junkyard and stripped some guages off of it. I installed the tach and moved to the smaller clock. I now want to install the oil pressure guage and voltmeter. I think I need to go back and get the oil pressure sensor. Is that correct or do I already have a pressure sensor? Where is it located? How would I install and wire up the two remaining guages - I know how to physically mount them in the dash - I'm not certain of the wiring. The tach and clock were very straigtfoward as the wiring harness was already prewired - I'm assuming that is not the case with the oil and volt meters. Thank you for your advice.