How do I check the temp gauge?

[wlbolerdo]

I've read posts here before on how to do it. I ground the temp switch wire with the key on and the gauge does what? Mine pegs on the other end of the gauge when I ground it. The sending unit is brand new.
Wayne

 

[wlbolerdo]

Re: How do I check the temp gauge?

Where was it moved to? I'm confused!

 

[waterinthefuel]

Re: How do I check the temp gauge?

It was moved to electronics and trolling motors, but it doesn't matter. If you click on your thread wherever you first put it you can still access your thread and view the replies. The fact that it got moved is irrelevant.

 

[Silvertip]

Re: How do I check the temp gauge?

So am I! Where was "what" moved to?? And what are we working on?? Outboard or I/O? A temp sender is nothing more than a variable resistor (called a thermister) that changes resistance as the water gets warmer and colder. So if you bought the correct sender (its not a switch), as the water temp gets hotter, the sender resistance decreases and the gauge reads higher. The opposite holds true. Therefore, if you grounded the "S" (sender) lead, the gauge should read "H" (hot) with the key on.

 

[wlbolerdo]

Re: How do I check the temp gauge?

Sorry about the confusion. It's a '92 70hp evinrude. I took the tan wire off the sender at the block and grounded it with the key on. It pegged on the hottest side of the gauge. Is the gauge good or bad or did I not test it correctly?
Wayne

 

[Chris1956]

Re: How do I check the temp gauge?

Wayne, There are two types of temp senders. Most outboards have a hot horn, and use a sender that grounds when it overheats. These do not work with gauges. If you have a gauge, the sender you need must change in resistance as the temperature changes. You may find a sender of this type for a I/O or automobile, or one may come with the guage upon purchase.

 

[Silvertip]

Re: How do I check the temp gauge?

Yes -- the tan wire you are dealing with is either on or off, there is no variability that a guage requires. Hook that wire back up so you don't defeat your alarm system. Here are two types of senders (you need one or the other) to operate with your gauge and the senders need to match the gauge. Both measure 30 - 240 ohms (hot-cold) depending on the engine temperature.

The sender on the left bolts to the cylinder head and technically becomes a "cylinder head temperature sender" and the gauge would read cylinder head temperature. The sender on the right screws into a port on the engine so the tip of the sender is in contact with the water in the water jacket of the engine. This is a true "water temperature sender" and therefore measure water temperature. Either type will work with a standard "outboard" gauge.