05 Civic Value Package oil light on and flickering
 

2005 Civic value package
1.7 L 5 spd.

Just had timing belt, water pump, coolant flush, spark plugs, PCV valve, camshaft seal, crankcase seals, oil and filter change using 10w-30 oil, and fan motor replaced.

I never had any issues with the car and being that I drive 137 miles each way to work (Fire Department), I need this car in tip top shape so I was being proactive. That being said I now have my oil light on on an intermitten basis. Meaning, it sometimes comes on at a cold start and flickers throughout the day, or it randomly comes on and flickers rapidly as if not making a connection. I brought it back to the shop and my mechaninc called around to find that the NON-honda crank seals are slightly smaller than OEM. I returned with an Honda OEM seal, same problem. Then tried a new oil sending unit, same problem. I crawled under the car to find the connection to the sending unit is rather shoddy, they "modified" it, but it is making a snug connection using the yellow wire with a red stripe on it. My oil levels are ok, just under the top dot on the stick, I observe oil being pumped to the head, no leaks anywhere at his time. Could it be the connection? A dislodged pickup tube, or debris at pickup tube? Another bad sending unit? Thank you all for your help in advance.