My Escort Redline detector - hardwired using a fuse tap - shows varying voltage (bouncing between 10.4 and 11.2V), and every so often (which is to say often enough) shuts down due to "low voltage" - essentially assuming that the engine is off. However, the actual battery voltage is fine, between 12.5 and 13V. So, is this an issue with the ground connection for the hardwiring or what?