Constant Alarm Sounding

[bwoodtx]

First off, thanks for a great website. I have learned much from reading these forums!

I have a 2008 Merc 4.3 TKS I am having trouble with and I can't seem to figure it out. I was on the lake Monday and the alarm started sounding. I checked the fluid levels and the gear lube reservoir was low. I added fluid and thought for sure this was my problem. My temperature and oil pressure gauges both read normal. The alarm sounds constant and stays on after the key is turned on, even before the motor has started. I disconnected the wires at the bottom of the the gear lube reservoir and still got the alarm.

Do any of you have any ideas of what I may be looking at? Thanks in advance for your help!

Brian

 

[Don S]

Re: Constant Alarm Sounding

There is also a temp switch and an oil pressure switch for the alarm system. They are not connected to the gauge like the sender is, they only operate the alarm.
You need to disconnect the temp and oil switchs like you did the reservoir to find out which one is causing the problem.

Assuming nothing has changed since 07. Was just looking at a wiring diagram, and not sure how the temp even gets to the alarm.

 

[bwoodtx]

Re: Constant Alarm Sounding

Thanks for the reply, Don! I downloaded the manual but couldn't ever find where the other two are located. Does the alarm still sounding when the wires were unplugged from the lube reservoir eliminate that as my problem?

 

[Rocky_Road]

Re: Constant Alarm Sounding

Thanks for the reply, Don! I downloaded the manual but couldn't ever find where the other two are located. Does the alarm still sounding when the wires were unplugged from the lube reservoir eliminate that as my problem?

Not so fast...if you have the key in the "ON/RUN" position...and the engine is NOT running...then the oil pressure switch will sound the alarm, even when the lube reservoir wires are disconnected.

The proper way to isolate the alarm is to pull the wires as the engine is running...one at a time.

Happy boating!

 

[bwoodtx]

Re: Constant Alarm Sounding

Yes, normally the alarm beeps three or four times then stops when I turn the key to the on position. Now it comes on and stays on.

 

[Don S]

Re: Constant Alarm Sounding

I'm not sure how the alarm works on the newer models. I haven't worked at a Merc dealership for 3 years.
But none of them ever beeped more than once for a system check and that was EFI engines.
I would suggest you check with your dealer, it should still be under the original 2 or 3 year warranty.

 

[bwoodtx]

Re: Constant Alarm Sounding

Thanks for the help guys. I believe my problem is with the sensor in the gear lube reservoir. Do you know if I can order the part online, or do I have to go through a mercury dealer to get it? I tried ordering it through the merc website but I couldn't get it to take.

Brian

 

[Rocky_Road]

Re: Constant Alarm Sounding

Thanks for the help guys. I believe my problem is with the sensor in the gear lube reservoir. Do you know if I can order the part online, or do I have to go through a mercury dealer to get it? I tried ordering it through the merc website but I couldn't get it to take.

Brian

If you are certain that the sensor is bad, then your best bet is to replace the reservoir. If you take a look inside the filler neck, you will see that the fitting is secured by a large nut...and the possibility of getting a wrench into the opening (only a crow's foot would work) and replacing this is slim.

I found a new one on eBay, and it was an original Mercruiser part and has been flawless. They are offered there all of the time.

You can also try taking the tank out...filling it with some solvent (gas comes to mind)...and seeing if the float frees up. The gear lube has a tendency to gum up after a few seasons, and may be keeping the float from moving freely. Can't hurt to try!

Happy boating!

 

[bwoodtx]

Re: Constant Alarm Sounding

Thanks for the help guys. It turned out to be my gear lube monitor. I had a bad sensor. I replaced the bottle and no more alarm!

Happy boating!

Brian