Perkins temperature gauge u/s

[acepi]

How do you test the sensor. Someone mentioned to boil some water, and chechk the resistance? The only test I seen on utube the person had a harness with two wires. .how do you hook up the the from the meter to where?
Thanks again

[S/V Antares]

On a single terminal connect the Ohm meter the terminal and body of the sensor and as you heat the sensor the value will change


If you have a floating ground sensor with two terminals hook the meter to each terminal and heat it up.


If I remember correctly the value is lowest when cold and gets higher with temp. A bad sensor will simply give no reading (Open) .

[leftbrainstuff]

Originally Posted by acepi

Thanks for all the help sofar just found out that I have been waisti get my time. What I thought was the temp gauge sender is in fact the sensor for the alarm. One person mentioned on another forum. It is supposed to be on the side of the engine. Any Perkins expert that would agree with that. Cannot find any manual on this

There is no standard arrangement for a perkins diesel.

You need to follow the wiring.

Your gauge will have a sender unit which will vary its resistance with temperature. You can use a multimeter to measure either the voltage change (in place) or resistance (in a pot of heated water).

Your alarm will probably have a switch. This just turns on or off.

I always check them in situ. I only remove components when I've diagnosed the fault.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[charliehows]

rig for testing electrics - length (up to 2m)of double insulated twin wire, alligator clips attached to each end of wires. To test sender in hot water - cooking or coffee thermometer to show water heat. clip test wire to wiring fitting of sensor and the other test wire to the body of the sensor, only immerse the body of the sender, attach other end of test wires to multimeter test prongs and set the meter to test resistance. As the heat rises the resistance should start changing. The temp sender can be tested in situ but you can't really test an alarm sender in situ unless you're prepared to overheat your engine.

[acepi]

Is there any person that can describe the procedure to check the sensor in hot water with a ohm meter? Much appreciated

[Cap Erict3]

Temp alarm for water usually set to trip +-10 below boiling. Try a coffee kettle. Immerse sensor in water. Fresh water won't hurt it.


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Looking for another pretty place to work on the boat.

[acepi]

Thanks for the reply. It's not the alarm I am testing. Just the temperature indicator. Tested the gauge and it seems to work. But if I do the test from the sensor wire at the sensor disconnected and ground the the wire, my gauge does not do anything .so that would indicate false wire or faulty gauge? Driving me around the bend

[Cap Erict3]

Temp sensor will look kinda like this. One wire.


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Looking for another pretty place to work on the boat.

[charliehows]

Originally Posted by acepi

Thanks for the reply. It's not the alarm I am testing. Just the temperature indicator. Tested the gauge and it seems to work. But if I do the test from the sensor wire at the sensor disconnected and ground the the wire, my gauge does not do anything .so that would indicate false wire or faulty gauge? Driving me around the bend

4 things to test; 1; sender unit, 2; gauge, 3; fuse, 4; wiring/connections
sounds like you've got 2 or 3 of them with a problem. Or 4 if the gauge only 'seems' to be working.
Are you using a multimeter?
grounding the sensor wire should produce a high temp reading if the gauge is working and the ignition is on. So you could have a bad connection or wire, which means there might be nothing wrong with sensor.

[acepi]

Went to the boat again today. Here is the million dollar question, which could solve my problem. With a ohm meter connected to the top connector with the red lead, and the black one to the bottom of the sensor, should I not get some kind of reading. In my case none? So is it the sensor?

[charliehows]

yep, because an ohm meter measures resistance you should get 'some kind of reading'. If you get no reading at all a; your ohm meter doesnt work or b; its not switched on. Whether your sensor works or not remains a matter of speculation.

[four winds]

The sender must be disconnected from the factory circuit to do an ohms test.

If still installed on the engine, removing the wire from the sender first will insure the meter is reading the sender and not the wiring harness. Which could read like an open circuit with the main switch off.

[acepi]

Correct me if I am wrong. Took the sensor out, with the ohm meter turned on, aha, put the black wire to the bottom of the switch, and the red probe to the top.nothing but a one on the ohm meter. Than I boiled some water, did the same reading and nothing. My question is , did I do this right, and as anyone doing the same test had different results.

[Cap Erict3]

The pic is for different sensor values through their range. The "1" you are seeing might be an indication that the reading is beyond your set scale.

I connect with an alligator clip on my probe to insure a good connection.

Was your initial problem a low, high or no change on your temp gauge?


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Looking for another pretty place to work on the boat.

[acepi]

The problem is no indication on the temp gauge. I tried all different setting and no luck. Tested the gauge and it seems to be ok.