cliffyboy

The SatNav and associated controls (air con, demister, etc) in my '53 Reg LS430 work intermittently. On initial start-up screen is blank and no controls work. Bluetooth message comes up and if the map button is pressed the message "external system is not connected" comes up. Radio works as does seat heating, ride height etc. After 40 miles or so everything comes to life, often for upwards of an hour or so but then, occasionally, all goes blank again. SatNav unit has been taken out and connections checked, no defects found. I would welcome any advice? Reluctant to purchase a replacement SatNav unit at £3,950. But for the uncertainty of the SatNav the car is a delight to drive.