2000 Mercruiser 3.0 - No temperature sender?

[MidwestFloater]

Hi all, I recently picked up a 2000 Sea Ray Bowrider 180 with Mercuriser MCM 3.0L a / L605518 serial variety.

I'd noticed that the temperature gauge on the dash defaults to ~170F, even when I'm just starting the boat. I was in the process of investigating other issues in the engine and found a number of wires not connected to anything. Upon further inspection and review of the wiring diagrams, it appears the temperature sender wire was not attached. I looked around for the temperature sender to connect it but couldn't find it. I found a capped hole next to what appears to be the oil pressure sender, but no temp sender. (see attached)

So a few questions:
Is that capped location the right spot for the sender?
Should I just be able to buy the sender part, put it in, and connect the wire?
Is having this slot capped normal? It seems like it doesn't make sense to put in a gauge but not a temp sender?

Thanks in advance!

 

[Bt Doctur]

what your holding is the wire for the temp sensor and it gets pushed on to the threaded stud, that is the temp sender

 

[MidwestFloater]

Thanks.

The way your are describing it is how it was connected. The wire in the prior picture is tan, and from the wiring diagram wire connecting to the temperature sender (switch?) should be tan/blue. There is an unattached tan/blue wire as shown in the next picture. So maybe the wires are just mixed up?

The wiring diagram also shows an oil pressure switch on the same wiring bundle (I think I got my terminology wrong, looks like these are supposed to be the audio switches, not senders?). So my expectation based on the wire color and appearance of the sender/switch made me think it would be the oil switch not temperature one.

Here's the wiring diagram I'm working off of: https://www.crowleymarine.com/mercury-outboard/parts/4893_60.cfm?mdl=FZLS1J

 

[Fun Times]

The plug on the left would be the location for the warning horn switch had it been installed from new/someone there after...Because the warning horn system was an option for the 3.0's.

The Tan/Blue wires are the warning horn system. The 2 tied back in your other photo would of been for the gear lube oil level monitor reservoir (Stern Drive Oil). The black boot for the engine temp warning horn.

Ignore the white wires in the following as they must have been added by someone I believe but for visual reference, https://forums.iboats.com/forum/eng...alpha-one-no-temp-gauge?p=3584130#post3584130
https://forums.iboats.com/forum/eng...desperate-need-for-help?p=3450032#post3450032

 

[MidwestFloater]

Ok cool, thanks much. So wiring seems correct then and I should follow the previously posted steps for troubleshooting the temp sender / gauge then?