The problem is we don't know how this testing is being done. If the bulbs are removed, even if there is a bad ground, 12 volts will still be measured with a voltmeter or a test light. All it would take is a tiny carbon track in a corroded connection and a voltmeter will pick that up as 12 volts. In this case a cheaper test light would be more accurate and would show 0 volts. If the bulbs are in place and the test point happens to be the ground side, there will be between 4 to 6 volts there because current will find an alternate path to ground through the tail lights and a different socket's ground wire. That means the supply wire is okay. If 6 volts is found on the supply wire when only one bulb is removed, there could be a high resistance connection. The clue would be found when the other bulbs are removed or the signal switch is moved to either direction to isolate the brake light bulbs on both sides. There's just too many variables and possibilities to make a good guess on how to proceed. There will likely be a real easy fix, ... IF we know what they did to find that 6 volts.
Saturday, March 26th, 2011 AT 4:08 AM