headlight not working

[rchurch5945]

I have a 96 Tahoe. My passenger side low beam quit working. I replace the bulb and it worked for about a week then went out again. Before I could replace it again it came back on for a day or so and went out again.

I pulled the bulb and the wire in it is still intact, so I tested it with an ohm meter and it showed continuity. I tested the connection and it has 10.5 volts to it. I tested it by putting the positive probe on the positive connection and the ground probe on the ground connection, which should tell me the ground is good also. The bulb still didn't work.

I replaced the bulb and nothing. What am I overlooking? I wear latex gloves when handling the bulbs so it isn't that.

 

[exp500]

Test the ground on ohms. You want 1ohm max on big wires(battery cables), .5 ohm on little for approximate numbers.
Low voltage to the bulbs really shortens life. For halogens I usually run new power wires to a relay near headlights and use existing headlight wire to trigger relay. Good luck and keep posting!

 

[Joseph Garcia]

I suggest that you take a very small flat head screwdriver and gently scrape the contacts inside the light bulb holder, to ensure that there is not a buildup of oxides on those contact surfaces.

 

[rchurch5945]

UPDATE: I bought a new bulb and connector. attached the bulb to the connector, then touched the connector wires to the battery terminals and the bulb worked. Cut the old connector out, tested the wires, 10.5 volts, attached the new connector/bulb, turn on the headlights - nothing!

I pulled the grill and traced the hot and ground wires back as far as I could. There were two places in each wire that were repaired by a splice. I cut the wires out ahead of the splices, attached new wires and attached the connector and it worked!

I still don't know why the bulb wouldn't work in the beginning when it showed there was 10.5 volts to it and a good ground. But it's working now!

 

[Joseph Garcia]

UPDATE: I bought a new bulb and connector. attached the bulb to the connector, then touched the connector wires to the battery terminals and the bulb worked. Cut the old connector out, tested the wires, 10.5 volts, attached the new connector/bulb, turn on the headlights - nothing!

I pulled the grill and traced the hot and ground wires back as far as I could. There were two places in each wire that were repaired by a splice. I cut the wires out ahead of the splices, attached new wires and attached the connector and it worked!

I still don't know why the bulb wouldn't work in the beginning when it showed there was 10.5 volts to it and a good ground. But it's working now!

Thank you for posting the solution to your issue. Much appreciated.

 

[Eman85]

You had 10.5 volts with no load on the wiring. As soon as the load of the light was on the circuit the voltage dropped. Glad you found your bad connection.