Help this darn oil light

i was wondering if someone could help me ive got an 81 xj650 and when i try to start it the oil light comes on and the starter doesnt engage now heres the kicker i unplug the diode in the headlight hit the start button and vroom but the lights dont come on so i plug it back in lights come on and it continues to run turn the dang thing off try to restart and the oil light comes back on no starter i just changed the oil and filter took out the oil level gauge knocked around a little but not to much cause i understand that it is a float type and the float was free moving now cut on the bike with no oil oil light on filled the oil and light went off i guess its working now everything is back together hit the switch no go all relays and such are working please help im new to bikes and anything electrical but i have a knack for small engines sorry about my grammer though any help will be greatly appreciated

 

The oil light should come on when you first start the bike. Just after starting it should go off. If it doesn't then it is either stuck, the wrong sender or the engine is low on oil. The senders from the 750's with a computer monitering system use a different sender that will always stay lit on a bike without the computer system. If this is not the original sender then I would suspect you have the computer type.

 

everything on the bike is original and you can tell by the poor shape the wire connecters are its just the fact that it was running so well and then the oil light just started doing this ohhhhhh i remember something now i blew a fuse to the main power you know the 30 amp and i didnt have another on to put in so i wrapped it in tin foil and threw it back in and i think i might have hooked the pos to the neg could that be the problem i might have burned something out for my carelessness
but why would it crankup and run with the diode taken out

 

Yikes! Get the proper fuse in there pronto! Possible fire hazard with that foil in there! I wouldn't leave that foil in there for anything, even just sitting there (though if I was 30 or so miles from home or the nearest sign of civilization I might have second thoughts). Get yourself a selection of spares and keep them with the bike. $2 for a kit from Bus-fuze.

 

yeah i know im not to brite when it comes to using common sense in electrical stuff took the foil out this morning before work had no time to put in the new ones had to put back together my brothers car anyways i read in a earlier post that a oil light bulb was lose and it caused the bike not to crank i dont know if thats true but ill try it out tommorrow sounds kind of funny what do yall think still dont know why it will crank with the diode pulled out but wont crank with it in