Mechanical Temperature Gage

[bobk]

On the trip to Florida the mechanical temperature gage for the port engine ceased to produce a reading. How does one go about diagnosing which part of the system needs reapir? Or do I just change the sender and gage? Where to buy it? Advanced Auto, Napa, Grainger?

I hate to say it, but there was a mechanic working on something else in the ER a couple of days before I noticed it.

Bobk

 

[GJH]

If you are in FL the first guys I'd call are Lauderdale Speedometer. They are very conversant with Hatteras gauges and controls. Sam's should have them too. Either should be able to help you troubleshoot before replacing.

 

[TopHattandTails]

Somebody please confirm this, but I have been under the impression that you can disconnect one of the wires to the gauge, ground it and if the meter pegs, it's the sender. If it doesn't peg, it's the meter.

...and X2 on Lauderdale Speedo.

 

[Boatnut]

If it's truly a mechanical gage there is no electrical sending unit, there is an oil line, if that is broken you will have an oil leak. More than likely you have a broken wire. Unless you buy a sender unit from the same manufacturer or the same manu. gage it's probably best to get and replace both as they need to match.

As for disconnecting a wire and grounding the wire from the meter may get you full deflection, but could also damage some meters testing it that way. Just touch the wire briefly to groiund and check for deflection, this is not a foolproof test but a good indicator, and usually will indicate a defective sender.

 

[Boatsb]

If its a mechanical gauge the wire is for the lights. The capillary tube is probably broken or kinked closed

 

[bobk]

No wires, just a very small diameter tube wrapped in a spring-like coil. Maybe it got pinched. Where does this lead me?

Bobk

 

[Boatsb]

Replace the whole unit with a new gauge and sender attached to the tube or some allowed you to run the tube separate. Pictures of the back of the gauge will tell the story.

Temp gauges only come in one piece. pressure gauges have the 2 options

 

[SKYCHENEY]

As stated, the capillary tube is probably cracked. You will need a need temperature bulb and tube.

There is fluid or air in that bulb. As it heats it creates pressure that moves the needle on the gauge. You have to replace the whole thing. This will mean getting the old bulb out and will probably mean draining out some coolant to do it.

Napa will have what you need.