MK3 Signal/ indicator/ flasher dash light

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Jerry Doe

Jerry Doe

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Hi All MK3 owners- question:

Not sure what you call it but the official name is the "Indicator Repeater Light". This is the small yellow light in the MK3 dash. I am making a custom wiring harness and not sure how this should be wired in. The MK3 drawing does not make sense to me. It shows the 2 wires from the bulb going to each left and right signal power feeds. I thought it had to be +- to work?? Can anyone confirm exactly how this dash light should be wired in?

Cheers- Jerry
 
Jerry Doe said:
Can anyone confirm exactly how this dash light should be wired in?
Click to expand...

What the wiring diagram shows is correct, for a "two-pin relay" flasher system, the warning bulb must be wired across the flasher circuits, and not + -, the actual bulb contact polarity doesn't matter (unless its an LED bulb in which case it may only work for one pair of flashers). :)
 
L.A.B. said:
What the wiring diagram shows is correct, for a "two-pin relay" flasher system, the warning bulb must be wired across the flasher circuits, and not + -, the actual bulb contact polarity doesn't matter (unless its an LED bulb in which case it may only work for one pair of flashers). :)
Click to expand...

Why will LED bulb only work for one pair?
 
dennisgb said:
L.A.B. said:
What the wiring diagram shows is correct, for a "two-pin relay" flasher system, the warning bulb must be wired across the flasher circuits, and not + -, the actual bulb contact polarity doesn't matter (unless its an LED bulb in which case it may only work for one pair of flashers). :)
Click to expand...

Why will LED bulb only work for one pair?
Click to expand...

LEDs are usually polarity sensitive. As the indicator warning bulb in this system is connected between the two (L/H & R/H) indicator circuits, the LED will flash for one side only, when the flashers/indicators on the opposite side are operated, the polarity across the warning bulb reverses so the LED doesn't work.

It is possible to get an LED to work for both sides, but that generally involves adding diodes and running one warning bulb wire to earth/ground. An alternative is to use a flasher relay with a warning lamp output terminal, however, not all 3 (or more) pin flasher relays will work with positive earth/ground.
 
L.A.B. said:
LEDs are usually polarity sensitive. As the indicator warning bulb in this system is connected between the two (L/H & R/H) indicator circuits, the LED will flash for one side only, when the flashers/indicators on the opposite side are operated, the polarity across the warning bulb reverses so the LED doesn't work.

It is possible to get an LED to work for both sides, but that generally involves adding diodes and running one warning bulb wire to earth/ground. An alternative is to use a flasher relay with a warning lamp output terminal, however, not all 3 (or more) pin flasher relays will work with positive earth/ground.
Click to expand...

L.A.B.

I assumed a diode was required...also am wiring negative ground.

Dennis
 
dennisgb said:
I assumed a diode was required...also am wiring negative ground.
Click to expand...

I have done it by connecting each indicator warning LED bulb "feed" wire to a diode with both "L/H" and "R/H" diodes connected to the same LED bulb terminal with the other bulb terminal going to earth/ground.

(Diodes and LED connected according to system polarity).

The four LEDs I bought (from RGM Motors) were not really bright enough, so I eventually fitted a set of standard MkIII warning lamps.
 
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