I have a very simple circuit to light up some 12V lights, specifically a dual filament 1157 tail light bulb. One of the filaments connect with the output of a relay for the brake light and the other with another set of connectors for rear tail light and one for headlight.
When switched on both the headlight and the tail light will turn on.
The brake light connected to the output of the relay didn't light when it should so to check this filament and the wiring to it, I plugged the leads for the tail light into the header that I know works for the tail light and headlight. When I do this, the bulb doesn't light.
I figured maybe one of the wires was broken so tested the continuity of the pair of wires for the brake light. For one of the wires I had zero resistance where the base of the bulb contacts the socket and infinite resistance for the two inside contacts. When I tested the other lead for the brake light I got zero resistance for one of the inner terminals and infinite resistance for the other inner contact and where the base contacts The wiring should be good. Thinking that it must be the bulb I tried several others and they didn't light either.
I then took a AC/DC converter rated 12V (I measured about 18V) and hooked its output to the two leads for the brake light and it lights regardless of which bulb I use.
I am baffled.
Does anyone have an idea what may be going on?
Thanks
When switched on both the headlight and the tail light will turn on.
The brake light connected to the output of the relay didn't light when it should so to check this filament and the wiring to it, I plugged the leads for the tail light into the header that I know works for the tail light and headlight. When I do this, the bulb doesn't light.
I figured maybe one of the wires was broken so tested the continuity of the pair of wires for the brake light. For one of the wires I had zero resistance where the base of the bulb contacts the socket and infinite resistance for the two inside contacts. When I tested the other lead for the brake light I got zero resistance for one of the inner terminals and infinite resistance for the other inner contact and where the base contacts The wiring should be good. Thinking that it must be the bulb I tried several others and they didn't light either.
I then took a AC/DC converter rated 12V (I measured about 18V) and hooked its output to the two leads for the brake light and it lights regardless of which bulb I use.
I am baffled.
Does anyone have an idea what may be going on?
Thanks