I have an 07 dyna fxd and recently the oil light came on. The engine has no out of the ordinary noises and seems to be running fine. First thing I thought is maybe the oil sending unit was bad so I replaced it and the light stays on. Of course i made sure the bike has oil. I tried testing the oil pressure with an old compression testing gauge I had but it showed 0psi and there is no way because I'm sure I would hear some bad knocking if that was the case. My next step is to get a proper gauge to test the oil pressure but is there anything else I should be looking into? Possibly something electrical? Prior to the light going on I rebuild my primary side,bearings,seals,stator,rotor,etc. The light has been on since I re did it but I didn't do anything to the engine side but the light has been on since the rebuild. Any input is appreciated thanks.

 

Harleys don't knock with no oil, but the lifters would fall and the valves would start to peck badly. However, I sure would not be running it till you checked the pressure at the light sending unit. Be sure you have proper Harley Filter.

Low Oil Pressure
1. Oil pan underfilled.
2. Faulty low oil pressure switch.
3. Oil pump O-ring damaged or missing.
4. Bypass valve stuck in open position.
5. Ball missing or leaking in cam support plate.

 

Look into your oil tank while it's running. If the oil is moving you have pressure.

 

Tank on Dyna is real hard to see.

 

Update : so I got a proper oil pressure gauge and my oil pressure is fine. Took the gauge off and then put the sending unit back on but the light was still on I reved the engine and then it flashed off and hasn't turned back on since. I'm not sure what caused it to come on but now it's off. Problem solved? Should I be worried that it just kinda fixed itself?

 

I would not worry about it. When you mix mechanical and electronics, glitches are electronics. It has oil pressure, always did. Don't put an antilog needle gage on it. That will drive you crazy.

 

Could have been an air bubble in the oil filter, figure if you were in the primary side you would do the full service while you are at it. . .

 

I just did the full service 40 miles ago which is what made me notice that I had the trans leak being the reason I did the primary side again.