If the Fuel Economy Guage Runs off the Vaccume line, Will that cause a difference in the heater/defrost/ac and or overall car performance? Also, is there a vacume hose inside the car I can splice off of, or should I just come off one vaccume point in the engene compartment. Which one. I just have the Guage and the wireing. So I will probably need to get some Vaccume hose, anyone know the size? Also, did volvo make a T for the Vacume line that I should get? What does it look like?

Thanks and Happy bricking