Water Temp Gauge

[biggerseagar]

I have a 01 3000 5.0L carb engines and my port side water temp gauge goes up about half way and stops.

I've checked the gooseneck with my infrared thermometer and same temp as the other engine after running both engines until the other gauge reaches operating temp.

I've wiggled the connection on the brown wire to where it connects with the temp unit with no luck.

Is it the temp sending unit that screws into the gooseneck housing that the brown wire connects to bad? Your thoughts?

Thanks

Roger

[gmc60]

swap them out gauge and sender see if they act the same

are the elbows in back of motors all the same temps or are they way off maybe flow of water slower on one side .

Good luck

[jrsick]

Roger, have you seen the temperature sender test on pg 4D -10/11 of service manual 24? The test involves measuring the sender's resistance at known temperatures. I did this test myself last year and discovered a faulty sender.

[biggerseagar]

No I have not....All I have is Clymers Mercruiser manual which is limited..like its reader LOL ! I did look up the temp sender unit that screws into the thermostat housing and they are very inexpensive. Heading to the parts store tomorrow.

Thanks

Roger

[donald]

Roger try grounding the wire at the temp sender and see if the gauge goes all the way to hot.
If not could be a bad gauge.
Just my 2c.
Don

[mmwjr]

Roger what is the temp half way up? My normal reading is slightly over half way but that’s 175 while my actual temp is ~160 which would b3 half way. Wiggling wire is not a good troubleshooting technique, remove the wire and clean its connection and reinstall. Mercruiser uses a t-stat gasket with brass eyelets to provide a ground and these become problematic.

Through away that manual and get the real Mercruiser manual under Documents of this site.

[jrsick]

That's the sender that I was referring to. Hopefully that works for you. If not, the gauge check is next.

[biggerseagar]

Thanks guys!!!

Roger