Testing a Temperature Gage???

[Solittle]

I have a pair of 1987 OMC crossflow V4s. I have a temperature gage for each engine. This is the type that is attached to one of the head bolts and has a cylinder about the diameter of a pencil the touches or nearly touches the top of the head and has a single wire attached to the other end. How do I test them?

 

[JUSTINTIME]

Re: Testing a Temperature Gage???

test in ohms
one lead to the sensor itself one lead to the wire, write down readings

next put sensor in a cup of hot water and do the same, write down the readings

i want to say as temp goes up resistance goes down

 

[rickdb1boat]

Re: Testing a Temperature Gage???

From the Teleflex site:

Testing the gauge for operation: Connect a hot wire to “I” and ground wire to “G”. Gauge should read
below the C. Next, short the “S” terminal to “G”. The pointer should go above the H. If the pointer sweeps
this way, the gauge is fine.
11. Testing the sender: At room temperature, with no wires on the sender, it should measure approx. 600-
1000 ohms on test meter.

 

[Texasmark]

Re: Testing a Temperature Gage???

Water boils at 212F at sea level, open container. The over temp alarm on my engine is set to close at 190F. So if you put your sensor in a container of boiling water it should show you where your overtemp spot is. After that just extrapolate to what is normal......120-140F.

Since most materials (sensors) are relative linear, I'd expect normal to be half way between off and hot.

Mark