I have a 2000 502mpi , when I turn the key on the alarm comes on and stays on the engine is not running when it is doin this. I have checked outdrive fluid and unpluged wires/ What else could it be

with the key on but the engine not running,the alarm shouls be on because there is no oil pressure,does it stop when you start the engine?

It usually just does the 2 or 3 beeps then stops, but now its just a straight beep for as long as the key is on. Last weekend was the first it did this and when this happend the starter would not engage I could here the solenoid clicking by the computer moved ground cable on battery it started. Yesterday pulled all cables off of battery,switch and starter cleaned and replaced.

the alarm system moniters oil pressure,water temp,and level of drive oil in resevour,if oil pressure is low,or drive oil is low,or water temp is high,the alarm will sound,and with the key on,but engine not running,the system sees no oil pressure,so the alarm sounds.the clicking,but engine not cranking is either a low battery,a bad connection,or a bad slave solonoid,or starter.