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Engine alarm

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ifusayso

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My engine alarm will not come

My engine alarm will not come on when I turn on my key. I have tested the alarm @ the oil resovoir switch and the alarm works. The alarm is getting power when I turn on the key. Everything seems to be wired correctly. Any thoughts would help. 2003 Bayliner w/mercruiser 4.3 liter
 
"Not sure what you mean by &#3

"Not sure what you mean by "I have tested the alarm @ the oil resovoir switch and the alarm works."

The high temp, low oil press, and low drive oil level switches are all NO, so that when any one of them closes, the circuit is completed to engine ground and the alarm sounds.

The alarm normally sounds when the key is turned on, as the oil press switch is closed before the engine starts.

So if you are grounding the oil sender wire with the key on, and that sounds the alarm, that means that the oil press sender switch is open circuit; it's shot.

Clear as mud?
Rod"
 
"In rereading your post, I thi

"In rereading your post, I think you mean that you grounded the wiring at the drive oil reservoir, and that sounded the alarm, right?

Since it does not sound with the key on otherwise, I would suspect the oil press switch is open circuit, per above, or the wire to the oil press switch is disconnected or broken. Check these items.

Rod"
 
Thank you for your reply. You

Thank you for your reply. You are correct. I grounded @ the drive oil resorvoir and the alarm did come on. I believe the switch is on the lower right hand side of the engine if you are facing the rear of the boat. Is there a way I can test the oil pressure switch to see if I need a new one?
 
"The oil press switch is on th

"The oil press switch is on the lower rear port side, just above where the oil filter (or filter adapter) is located, just in front of the exhaust downpipe.

There are two senders. One is for the oil press gauge, and the other is the alarm switch.
The alarm switch should have a tan/blue wire hooked to it. It is a small brass or black colored cylinder about 1.25" diam x about 2" long, with a wire coming off the end.

Suggest first check to see that the wire is connected. Then with the key on but engine not running, disconnect and ground the wire with a jumper. If the alarm sounds, the wiring is good and the switch needs replacing. If not, suspect the wire is bad somewhere.

Try with a VOM between the switch terminal and the case (ground). There should be continuity if the switch is good.
If the switch is good and grounding the wire won't activate the alarm, the wiring is bad somewhere.

Rod"
 
"Thank you for your help. My

"Thank you for your help. My local dealer gave me the normal response..."Bring it in and we will check it out.(interpreted this means..." we will have your boat for 2 weeks, replace a few sensors, and send you a bill for $200.00") I will let you know how this turns out. Thanks again."
 
"Brian;
I have the exact same

"Brian;
I have the exact same problem with my 6.2 MPI that I installed last spring.
So in thinking about your issue, I now have a good idea what to check on mine. Either the switch or the wiring is bad. It pretty much has to be one or the other.
This will be first on the action list when getting the boat ready this spring.

Rod"
 
"OK. I cannot find the sensor

"OK. I cannot find the sensor. On the port side by the oil filter I found a oil pressure sensor that had a purple and a purple/white wire attached via a harness. When I jumped these wires I heard my fuel pump come on. Screwed into the side of this sensor was my oil sending unit going to the gauge. I looked everywhere for the oil pressure switch with the tan/blue wire and couldn't find it anywhere. I tried tracing the tan/blue wire from the harness and can only find where it ties to drive unit oil resorvoir, distributor, and a ecm (a little black box with two wire harness connections). Is there any other place this DAMN sensor would be. On the wiring diagram there shows to be two sensors and one sending unit."
 
"It may be on the rear top of

"It may be on the rear top of the engine, just to the port side and behind the distributor. Sometimes one of the sensors is stuck up there. It should look the same as described.

The sensor you jumpered is the oil pressure switch that cuts the fuel pump out if the engine loses oil pressure. Sounds like it is working as intended.

Rod"
 
"Well, I found it. Finally!!!

"Well, I found it. Finally!!! It was behind the distributor. Tested the wire and the alarm went off so it must be the sensor. I am ordering a new one today. No local dealer has the part in stock. Thank you so much for all your help!"
 
Brian;
Sounds like you have i

Brian;
Sounds like you have it under control. Hope the new one works out for you.
Happy boating.
Rod
 
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