How do I test a temperature gauge?

[annapolisdan]

I keep reading posts about how to test a temperature gauge but I am still confused. When someone says ground the sending unit to see if the gauge spikes, does that mean ground on the back of the gauge itself or down at the engine block? If on the gauge itself, should I remove the connection on the sending unit post on the back of the gauge and then connect a wire from the 12V input post to the sending unit post? Could I do this instead with a standard 12V tester with alligator clip? If anyone has pictures, that would be great. Sorry if this is a basic question, but trying to learn how to troubleshoot things myself without the mechanic. Thanks.

 

[Rocky_Road]

Re: How do I test a temperature gauge?

I keep reading posts about how to test a temperature gauge but I am still confused. When someone says ground the sending unit to see if the gauge spikes, does that mean ground on the back of the gauge itself or down at the engine block? If on the gauge itself, should I remove the connection on the sending unit post on the back of the gauge and then connect a wire from the 12V input post to the sending unit post? Could I do this instead with a standard 12V tester with alligator clip? If anyone has pictures, that would be great. Sorry if this is a basic question, but trying to learn how to troubleshoot things myself without the mechanic. Thanks.

Easiest way is to just take the lead off of the sending unit, and touch it to the engine block...with the key in the "ON" or "RUN" position. You can also leave the wire attached and take a alligator clipped wire and go to the block. This will also test the wiring to the gauge.

Happy boating!

 

[Don S]

Re: How do I test a temperature gauge?

Easiest way is to just take the lead off of the sending unit, and touch it to the engine block...with the key in the "ON" or "RUN" position. You can also leave the wire attached and take a alligator clipped wire and go to the block. This will also test the wiring to the gauge.

Make sure you ground the wire to a CLEAN metal surface, not on a painted surface. I had people show me how they tested things by grounding to paint. Just doesn't work.