My headlights are not getting the proper volts
If the lights are dim, the first place to look is the ground wire coming from the light bulb socket. Often the ground terminal attachment to the car body is corroded (there may be a separate ground wire for each lamp - check both). If this is the case, take the connection apart and clean off the corrosion and dirt. Scotch-Brite abrasive sheets work well for this purpose. Sandpaper is too rough for the job; it either takes off too much metal or it doesn't get down into any pits or steps in the metal. If the ring-shaped terminal is severely corroded (broken, ready to break, or stripped bare of zinc or tin plating), replace it. After screwing the terminal back into place, cover it and surrounding bare metal with grease or sensor-safe silicone rubber (ordinary RTV or caulking emits gases while curing that will poison your oxygen sensors, even in small amounts).
Next, check the headlight connectors. If they are heavily tarnished, they should be cleaned and polished. You may have to wrap a strip of Scotch-Brite around the end of a thin flat-blade screwdriver to polish the terminals inside the connector sockets. Likewise, clean the terminals on the headlights if needed.
If all of the headlight terminals and wires are in acceptable condition and the lights are still dim, the contacts in the headlight switch may be burned (excess contact resistance). You can check this by comparing the voltage at the battery terminal with the voltage right at the headlight (headlights ont). If it is much less, that is most likely the problem (it could be an issue with the headlight fuse socket or circuit breaker, but that is very rare).
Sep 10, 2011 |
2004 Chevrolet Impala