rtcosic
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I am trying to upgrade the indicator/semaphore circuit using LEDs and solid-state flasher units in accordance with this wiring diagram:
On my first attempt, I was finding sympathetic slight flashing of the left rear (lowest power) indicator when the right indicator was selected. Additionally, the right flasher unit emitted half-hearted random ticking noises when the switch was returned to the central position.
Swapping flasher units made no improvement.
I thought I might have issues with the loom or the diodes or the flasher units or the light units or the LEDs.
Disconnecting all the flasher units and associated items and the switch then applying power to each lamp circuit in turn showed everything working as expected.
I wired up a complete test circuit on the bench and all worked perfectly. So I haven't damaged the flasher units or diodes.
Today I tested the steering column switch whilst it was disconnected from all circuits. I used a little AVO M806 meter in the 'diode test' mode.
I got the following results:
Connected between input power and right output - colour codes 17 & 21 above:
Switch in Central, neutral, position: c. 0.5V no sound
Switch in Left: c. 0.75V no sound
Switch in Right: c. 0.3mV, continuous beep
Connected between input power and left - colour codes 17 & 18 above:
Switch in Central, neutral, position: exactly 2.60V repeatably
Switch in Right: exactly 2.60V repeatably
Switch in Left: c. 0.3mV, continuous beep
When I added just the flasher units themselves with no connected load when selected:
left one emitted clear ticks at the correct frequency and was silent when not selected
right one emitted clear ticks at the correct frequency but emitted half hearted ticks at random when not selected
Swapping flasher units over didn't change the outcome.
I've got something odd going on with the selector switch or the wiring inside the steering column, haven't I? Disassembling 70 year old Bakelite and 2 meters of equally old and fragile internal column wiring is something I want to avoid.
Do the recorded values help with a diagnosis?
On my first attempt, I was finding sympathetic slight flashing of the left rear (lowest power) indicator when the right indicator was selected. Additionally, the right flasher unit emitted half-hearted random ticking noises when the switch was returned to the central position.
Swapping flasher units made no improvement.
I thought I might have issues with the loom or the diodes or the flasher units or the light units or the LEDs.
Disconnecting all the flasher units and associated items and the switch then applying power to each lamp circuit in turn showed everything working as expected.
I wired up a complete test circuit on the bench and all worked perfectly. So I haven't damaged the flasher units or diodes.
Today I tested the steering column switch whilst it was disconnected from all circuits. I used a little AVO M806 meter in the 'diode test' mode.
I got the following results:
Connected between input power and right output - colour codes 17 & 21 above:
Switch in Central, neutral, position: c. 0.5V no sound
Switch in Left: c. 0.75V no sound
Switch in Right: c. 0.3mV, continuous beep
Connected between input power and left - colour codes 17 & 18 above:
Switch in Central, neutral, position: exactly 2.60V repeatably
Switch in Right: exactly 2.60V repeatably
Switch in Left: c. 0.3mV, continuous beep
When I added just the flasher units themselves with no connected load when selected:
left one emitted clear ticks at the correct frequency and was silent when not selected
right one emitted clear ticks at the correct frequency but emitted half hearted ticks at random when not selected
Swapping flasher units over didn't change the outcome.
I've got something odd going on with the selector switch or the wiring inside the steering column, haven't I? Disassembling 70 year old Bakelite and 2 meters of equally old and fragile internal column wiring is something I want to avoid.
Do the recorded values help with a diagnosis?