Q: How do you troubleshoot an inoperative tail light, running light, or side marker light on Honda Prelude?
A: For an inoperative tail light, running light or side marker light for instance, you should first check battery voltage and ground to the electrical connector of the light. If voltage is available at the battery, check the bulb socket and the electrical connector ground terminal for continuity. If both are present at the light connector but None in the socket, then clean the socket and ground terminal connector. If voltage is present and ground is good in the bulb socket then replace the bulb. Also check the function of the light switch and where necessary replace it. For the use for an intermittent basis, check for a broken filament and for this replace the bulb accordingly. Check whether there is any corrosion on the bulb or socket if yes clean or replace them respectively. Search for the loose, damaged, and the corroded cables and terminals and fix them and the light switch may also be faulty and worn hence may need to be replaced. In the event that the light is very poor, try to assess the condition of the bulb and the socket especially for traces of corrosion and if so proceed to clean or replace them as the case may be. Check poor light output at the socket positive terminal or bad bulb connection; if the voltage is low or ground is marginal test wiring for loose or damaged or corroded positive wire and electrical terminals and correct as necessary. Last is the light switch, where one is required to test the functioning of the switch and replace it if faulty.