gearhead

when i was a kid, i used to take things apart and put them back together again. it started out with an old telephone, but my parents had to intervene when i took the back off the television set. my favorite toys were legos and construx and my first career ambition was to be a brick house builder, because those legos were so damned fun. then i decided i wanted to be an architect and somewhere along the line that changed to engineering.

i always liked solving problems and i still do. on sunday afternoon, i fixed two things on my old volvo -- i replaced the oil pressure sending unit and repaired the fuel gauge float and sending unit. the oil pressure sending unit plugs into the side of the engine block and costs about $4 at autozone; i'm not sure how it works, but there is a single lead that goes to a light in the dash. if there is no pressure (or of the sending unit goes bad, which is what happened to the old one) the light comes on. i guess there's some sort of diaphram that moves and opens the circuit when there is pressure.

but the fuel gauge is more complicated, and you can't actually buy the thing any more. the assembly consists of a float on a little arm attached to a variable resistor and the whole thing drops down into the gas tank through a hole in the top. a single wire connects the resistor to the gauge in the dashboard and the circuit is completed through the universal ground (many car electronics are just grounded to the frame; instead of running two wires from the gauge to the sending unit, only one wire is needed if both the gauge and the sender are grounded to the frame). anyway, as the fuel level changes, the position of the float changes, which makes contact with a different spot on the variable resistor, which changes the current going to the gauge in the dash, which results in me not running out of gas unexpectedly. well, the float assembly was so badly rusted that is was no longer being properly grounded -- which meant i had no idea how much fuel was in the tank, aside from guesstimating based on my odometer. so i took out the float, dismantled it, cleaned it, put it back in and viola! -- my fuel gauge works!

so yeah, solving technical and mechanical problems has always given me great satisfaction. but calculus takes the fun out of just about anything, which is something i failed to consider back when i thought that my affinity for fixing things meant i would like being an engineer.