I have installed a Prosport oil temperature gauge and installed it above the 3rd cylinder as per this guide
http://www.scoobynet.com/interior-15...and-boost.html
It rises and drops as it should with driving but I have noticed that when using any of the cars electrics such as windows, air con etc. the gauge rises by quite a lot (can be up to 30 degrees). Is this a faulty gauge, is it normal for a cheapish gauge to do this or is it my installation (I assume its the latter). I have earthed it very close to the gauge on the engine block where another earth was already in place.
I don't really want to take the sensor out to put into boiling water to test it, it was enough of a pain installing in the first place!