12 Volts but bulb doesnt light

04 Honda Civic · 09-23-2009

I know its not a Honda lol. But I just bought a 1988 Nissan Sentra in manual so that I could learn how to drive stick. Since my civic is automatic and I just wanted a beater to learn on. I am having trouble with the third brake light. For some reason I cant get it to work. I have gotten all of the other lights to work by simply just changing the bulbs. I changed the bulbs in these two sockets as well with brand new bulbs, but nothing. So I removed the bulbs and check for power I am getting 11 volts there. I dont understand whats going on. Is it the amperage that is not getting there? Any electrical guys give me ideas.

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CraigW · 09-23-2009

Could be an open ground... Are you measuring voltage on both terminals ?? If voltage is present on both sides check the ground or provide a ground with a jumper as a quick test.

04 Honda Civic · 09-23-2009

I jumped the ground with no luck. Used a few different grounds too. I get 12 volts on both sockets. As soon as I put a bulb in one socket the 12 volts dissapears from both sockets. I am not 100% sure whats going on but I know there is probably only 12 volt signal and no amperage to the sockets. Any ideas on what to do?

CraigW · 09-23-2009

Do you have a 12v test light ??
It will provide a load for the circuit. You could also check continuity for the ground and continuity between the other bulbs that are workings hot lead and the high mounts hot lead.

gearbox · 09-24-2009

hmm usually the 3rd brake light is tapped off the wires on either the left or right side brake bulb. so maybe retrace those wires. its possible the socket is messed and not making good contact, or they are touching together idk.

electric130 · 09-26-2009

i used to see this on aircraft in the Air Force. you'd measure good voltage, but the component would work. it was usually broken wire strands on a connector. say a wires got 15 strands. if all are broken but 1 or 2, you'll read voltage, but theres not enough of the conductor to carry the load. so i'd give the wires at each connector a good hard tug. if they're good, you wont damage them. if they're weak or broken, they'll come out and you'll know where the problem is.