Mark

We recently had a pitot probe that was not pulling enough current in the low power mode to satisfy the current flow relay. The associated overhead warning light and EICAS message were on. The probe "was" getting hot

This problem was noted by the crew right after the first engine was started. The engine speed cards are what turns on the probes in a low heat mode.

When the aircraft was placed in the "air" (or high power) mode, the failure indication was gone. It also was gone when trying the probe heat test switch.

After wasting about an hour chasing relays..... we hung a new probe on the connector and tried low power..... it worked normal.

After digging into the print, it was noted that the test switch puts the probe in a high heat mode.