I installed the TP-3 on a Rolls-Royce Merlin to monitor my Coolant Temp and Pressure, it worked fine for about 25 hours then the RIGHT sensor started reading over 200C…..Removed the cowling and the wire was no longer secured to the sensor, it appears the wire is secured by a sealant. I re-secured and get similar readings…..any suggestions? New Probe?
Left Bank Coolant Reads 88C
Right Bank Coolant Reads 201C
TP-3 - Excessively High Coolant Temp
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Re: TP-3 - Excessively High Coolant Temp
Since you have two probes - just swap the channels (i.e. move the wires over). If the issue flips to the other channel - it would appear your probe is no longer working.
Since you are using NTC senders you can also use a resistance meter - disconnect the wires from the probe and measure the resistance of the probe to the engine block - you should get the same reading on both probes. I high resistance means LOW temperature. Typically these senders would read in the region of 80-100 ohms at operating temperature - perhaps around 2KOhms at ambient. Varies between different sensor types of course but you can use this as a guide line.
Since you are using NTC senders you can also use a resistance meter - disconnect the wires from the probe and measure the resistance of the probe to the engine block - you should get the same reading on both probes. I high resistance means LOW temperature. Typically these senders would read in the region of 80-100 ohms at operating temperature - perhaps around 2KOhms at ambient. Varies between different sensor types of course but you can use this as a guide line.