I have installed a Prosport oil temperature gauge and installed it above the 3rd cylinder as per this guide https://www.scoobynet.com/interior-1...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.