3.0 Carb Temp Sensor

[mesteve]

We recently purchased a Sea Ray BR180 with a carbed 3.0 Merc/Alpha. The engine temp gauge did not work on purchase. Doing some digging in the shop manual I find the temp sending unit is on the port side of the thermostat housing. Looking there on my engine i find no sending unit and the tan wire identified on teh wiring diagram as the one that should be connected to the sender just hanging, semi tied out of the way.

Assuming (i know that's dangerous) that having the temp gauge on teh dash would mean there is a corresponding sending unit on the engine...

What am I missing?

 

[dubs283]

Re: 3.0 Carb Temp Sensor

all merc sterndrives come factory with a temp sender and wiring

it is in your best interest to install a sender and connect the wire and ensure the sender/guage is working properly

 

[mesteve]

Re: 3.0 Carb Temp Sensor

I don't see a place in the housing for a sender to thread in. Just to make sure I am looking at the right place, it should be front and center on the top of the motor. There is an engine hoist mount on bolted to the top.

 

[Don S]

Re: 3.0 Carb Temp Sensor

You could start by giving us a Serial number for your engine so we can ID your engine. Not all 3.0L wiring and thermostat housing are the same.

The wire that is tied back, are you sure it's not tan with a blue stripe ?

 

[mesteve]

Re: 3.0 Carb Temp Sensor

It looks to be M or N 049245, The sticker on the carb is worn, but appears to jive with the block tag.

In that bundle, there are 2 tan/blue disconnected one with a bullet connector, the other with a right angle, a black with bullet and a solid tan. I did find a threaded stud sticking out of a larger bolt head shaped protrusion on the fromt of the thermo housing witin reach of the tan wire.

 

[dubs283]

Re: 3.0 Carb Temp Sensor

I did find a threaded stud sticking out of a larger bolt head shaped protrusion on the fromt of the thermo housing witin reach of the tan wire.

that is the temp sender

connect the tan wire with the 90 degree black end to the the stud and check operation of the guage with the engine running/warm

 

[mesteve]

Re: 3.0 Carb Temp Sensor

Thanks, will do.

 

[Don S]

Re: 3.0 Carb Temp Sensor

It's an M in your serial number, and it's a 2001 engine.

 

[mesteve]

Re: 3.0 Carb Temp Sensor

Well, that's good, its a 2001 hull!

Thanks for the help.

 

[mesteve]

Re: 3.0 Carb Temp Sensor

On a side note, still talking about disconnected wires. I am guessing the others in the area are supposed to be unused with my motor, head temp sensors, high temp alarm etc?

Actually, it looks like the Tan/Blue should go to the outdrive oil resevoir and maybe an oil pressure switch and the black to the outdrive oil resevoir?

 

[Don S]

Re: 3.0 Carb Temp Sensor

The tan/blue wires are for the alarm system (optional equipment) for high temp, low oil pressure, and low gear lube reservoir, and yes the black would be for the oil reservoir.

 

[mesteve]

Re: 3.0 Carb Temp Sensor

Ah, so since they are all disconnected, I will assume I do not have the optional alarm. Again, thanks for the help.

 

[Rocky_Road]

Re: 3.0 Carb Temp Sensor

Ah, so since they are all disconnected, I will assume I do not have the optional alarm. Again, thanks for the help.

Mine were also disconnected, but I found the buzzer installed under the helm. All that I needed to have the complete system were the temp switch (goes next to the gauge sender), the low oil pressure switch, and the drive lube reservoir with the sensor wires.

Here is the 'buzzer' that was under the helm: