After engine rebuild and added an aftermarket oil cooler I see red light coming up after a few minutes of engine running. Obviously I shut the motor right off. Did not have a chance to install the proper oil pressure meter or do other diagnostics. So, I wonder if I did something stupid while engineering an oil cooler size or line size. The ones I use are AN6 and oil cooler is about over 24x12 inches. I was trying to replicate the OEM size, which I have seen only on pictures I dont want to risk running the engine with red light on in case the oil cooler is empty and requires time to fill in. What would you do in my case? I could install a bypass line or put the N/A oil filter plate back to eliminate the oil cooler completely. If I shut the engine off and let it cool, everything is normal. Engine starts, light goes off until it warms up again.