2G tachometer only works when its cold 95 tsi

[FirstDSMTimer]

Ok guys ive been driving the car like this for a few months now. I get a reading in link so my ecu is good and ive replaced the power transistor. when the weather is dry and cool i have a working tach but as soon as it gets humid and hot its doesnt want to work. anyone have any insight? thanks in advance.

 

[Lolmooses]

Sounds like a resistance issue as heat causes higher resistance, but it could very well be a faulty gauge cluster or something to do with a sensor that tells the ECU what RPM the engine is running at. I'd look up what tells the ECU the RPMS and how it translates into a reading to the gauge cluster.