How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Jason Your Own Question
Jason
Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 15673
Experience:  Degree in Marine Technology. Gas and diesel marine mechanic.
44667847
Type Your Boat Question Here...
Jason is online now
A new question is answered every 9 seconds

I have a 1999 mercruiser 5.0 mfi serial # ***** The audio

Customer Question

i have a 1999 mercruiser 5.0 mfi serial # ***** The audio alarm is sounding as soon as you start it up. The gauges read oil psi about 38 and water temp 170 when at operating temp. The outdrive oil is full and with the wire off alarm continues. I have no continuity with bottle full. could you tell me where the temp. and oil sensor are and how to check them. Any other test would be great. I test the alarm its self by grounding it out and it checked out ok. Thanks
Submitted: 1 year ago.
Category: Boat
Expert:  Jason replied 1 year ago.
Hi Dave, my name is***** the alarm a constant beep, a beep over and over, or a pattern of beeps that repeats itself every minute?
Expert:  Jason replied 1 year ago.
Hi Dave, are you still with me?
Customer: replied 1 year ago.
YES I'M STILL HERE WOULDN'T LET ME ANSWER YOU FOR SOME REASON IT'S A SINGLE BEEP EVERY COUPLE OF SECONDS
Expert:  Jason replied 1 year ago.
If you disconnect the 2 wires that into the monitor bottle does the alarm stop?
Customer: replied 1 year ago.
NO IT DOESNT
Expert:  Jason replied 1 year ago.
Okay. The oil pressure switch is located on the side of the engine block, just above the oil filter. There is a single tan/with a blue stripe wire on this. The temperature switch is located at the thermostat housing, and has a single yellow wire on it. What you want to do is unplug them one at a time and see if either of them silences the alarm. Whichever one silences the alarm is the bad sensor. If the alarm still sounds with both switches disconnected, then there is going to be a bad EFI sensor on the engine, and the engine would have to get hooked up to a scan tool in order to figure out which one it is. Does that make sense to you?
Customer: replied 1 year ago.
I HAVE A REMOTE FILTER AND AT THE ORIGINAL FILTER HOUSING THE SENDING UNIT HAS A GRAY WIRE THERE ARE 2 SENDING UNITS ON THE THERMOSTAT HOUSING ONE WITH TWO WIRES AND ONE WITH A TAN WIRE I UNPLUGGED ALL THREE AND THE ALARM CONTINUES THE SINGLE WIRE UNITS KILLED THE OIL AND TEMP. GAUGE
Expert:  Jason replied 1 year ago.
Is there a switch down on the right hand side of the engine, where the oil filter typically mounts?
Customer: replied 1 year ago.
YES
Expert:  Jason replied 1 year ago.
If the wiring is all original that switch should have a tan with a blue stripe wire on it. Does yours have that color wire on it? If yes, does disconnecting that make a difference?

Related Boat Questions