Boost gauge electronics problem

G'day, excuse the crappy wording and/or format if you notice any, this is typed on an iPhone.

I have a 52mm defi boost gauge connected to my mkv gti which sits in an Osir pod in the drivers side aircon vent. All wires are firmly connected and works perfectly. The problem is that when I park my car in the sun (Brisbane recently had a 28 degree day in winter) for a long period of time like when I'm at work, when I get in my car and start the engine the boost gauge seems dead, not lights come on and the needle doesn't move.

Yet when the car 'cools' down say when I park it at home in the shade for 2-3 hours and then start the car and drive it, it works perfectly. I noticed this only occurs when I park the car for long. Periods of time in the heat/sun.


Does anyone have any ideas why this would happen?

Most likely a bad connection somewhere (solder joint?) that expands when it gets hot and breaks contact.

Might also be a heat-sensitive component in the gauge — small enclosures like those can get really hot in direct sun.

Try shading it when you park the car.