Picked up my '81 300SD Turbo that I included
 

in my sig a couple weeks ago. Title was held up for a bit. Ash tray/lighter has never been used. Has 244k+. Only thing found so far that does not work correctly is the oil pressure gauge. It pegs high needle at key on. I unplugged the wire to the sensor at the bottom of the oil filter(thanks, search engine, for the location) with no change in the gauge. Will search/explore more tomorrow.

Any hints from anyone on where to look for short?

Tach also not working. Tried search and also checked alll the way back to pg 14, no see - Not too long ago was an entry about using some packing between the garbage can lid, on the fender well, and the ckt board under it. Can someone steer me to that thread, please?

TIA,

Fixed both troubles this morning
 

Metered the oil sending unit. It read 15 Ohms to ground, w/engine stopped and 150 Ohms with engine running. Gauge metered 7.5 Volts to ground with key on & pressure switch unhooked. Reconnected, traced wire to left fender well, removed/reconnected three connectors at harness end, both units work as designed. :)

Maybe this will be useful to others.... Now - on to rusted battery tray. :eek:

Oil pressure gauge continued working, tach quit -
 

Took the base of the garbage can apart and the part that holds the female sockets has disintegrated. Some of the metal sockets have also broken so that they have no tension on the male pins. These items are from the pickup coil at the harmonic balancer and I see that the sensor and wiring are available. The sockets from the other unit(don't know what it is as yet) are also brokenMay have to find some females and solder them to the existing cable..

Battery tray out and what a mess! Waiting on the Rust Bullet I ordered as recommended in an earlier post. I have some Chem Prep that has phosphoric acid but thought I would wait on the bullet.... :eek:

My battery tray could use a replacment also... any clues?