Im having an issue with my guages basically if the car is on and idling in park all gauges seem to be acurate, however if you press the brake they drop a few notches, and if you put it in DRIVE the gauges drop even more. what should i look for? How much would it cost to have someone just replace the underdash harness? Oh also the speedo when i accelerate it will go like it should as soon as I let go of the gas it drops to Zero, i was told the entire cluster was bad but wanted some other thoughts.