83 300SD Fuel Lines & Sending unit Help

[dbdoc]

I have recently purchased a 300SD and want to install a fuel line heater and filter for using WVO. Can someone help with which fuel line is the feed and which line is the return fuel line, what about the "cigar" hose???

I have already cleaned the fuel level sender, it was at 1/4 tank when I ran out of fuel. BTW on a 83 300SD the sender is removed by taking the back seat out not the first aid box!!!

Now the sending unit will not work at all, it did before. Are the two thin wires, like fishing line, what send the signal or is it the center post?
When I opened it up it was full of gunk and one of the "thin wires" was broken.

Any help will be appreciated.
Doc