Audio Warning System - High Temperature Switch Problem?

[2xsl_1998]

Hi all. I was out this weekend, and my audio engine warning system started going off. The tone was continuous, and the owner's manual says that this is caused by one of two conditions: 1) low oil pressure, or 2) high engine temperature.

My oil level is ok, and the oil pressure gauge indicates normal range. My temperature gauge is in the normal range as well.

I managed to find the oil pressure switch for the warning system and disconnecting it did not make the alarm stop. When I disconnected the high engine temperature switch, the alarm did stop.

What has me puzzled is that the problem is intermittent. My gauge never indicated that the engine was overheating.

Can the temp switch be sticking or something? Is it a normally open or normally closed switch? I have an ohm meter to check it with.

The boat is a 2005 185 Sport w/4.3L 190hp, has about 96 hours on it. Thanks in advance.

 

[teamgomez]

Went thru a bit of troubleshooting on my boat for same reason...while I was hoping that it was the temp alarm switch...turned out to be a poorly installed pump in the outdrive.

I removed both the temp sender and the alarm switch and dropped them in a pot of hot water. Check for switch closure at specified temp (mine is 190 deg) and check resistence of the temp sender at various temp ranges (specs in the SELOC repair manual).

Don't know if this helps but got me going down the road to my ultimate solution. Good luck!

~John

 

[comsnark]

Yeah. . .always blame the instruments FIRST, because they are cheaper to fix.

The boat has two temperature sensors: one wired to the gauge, one to the alarm. ONE of the sensors is wrong. Hopefully, it is the one in alarm!! I recently bought a IR temperature gun from Sears for $80. I would suggest checking engine temps to verify this is a sensor (not an engine) problem.