Merc 3.0 - Temperature and Audio Sending Units

[Mikejr]

2005 Mercruiser 3.0, Alpha Drive.

Just finished replacing the rocker cover gasket and removed the Water Temperature (audio) and Water Temperature Sending unit wires from front of thermostat housing, but failed to tag them. Without taking each out and breaking the seals etc., is there an easy way to visually identify the Audio unit from the temp sending unit? I have the wiring guide, but don't know which is which visually.

Also, there is a third wired brass unit plugged into the port side of t-stat housing - what is this for?

Please see image with questions.

Many thanks to the community!
Mike

 

[Don S]

Re: Merc 3.0 - Temperature and Audio Sending Units

The one on the right should be the gauge sender and have the tan wire on it.

Take the wires off and post another picture. Hard to see the switch and sender with all the wires and connectors in the way.

 

[Mikejr]

Re: Merc 3.0 - Temperature and Audio Sending Units

Don - here are two pictures from tonight (just realized I didn't pull the wires - can do in the am). Not much light out there now, so if these don`t show enough I`ll take fresh pics tomorrow with daylight. Do you know about that third fitting on the port side of the stat?