Turn Signal Indicator light Issue

[69GhiaRat]

I am having issues with the turn signal indicator light on the speedometer. It does not light up to show when the turn signals or the hazard lights are on when the car is running. The strange part is that it does flash and work properly if the key is turned to on but the car is not running.

I tried changing out the bulb holder thinking maybe it wasn’t getting a good ground but no luck, it still doesn’t work..

Any thought on this?

Richard
1969 Karmann Ghia

[runamoc]

That dash indicator light has 12v + on the 'side' of the bulb that comes from the key being on. When the flasher is supplying power to the turn signal bulbs and they are 'lit' there is 12v + on both sides of the indicator bulb. So, it's not lit. When the flasher 'cuts' off the power to the turn signal bulbs the indicator bulb 'loses' the power it was getting from the bulbs side of the flasher. The turn signal bulbs now supply a ground for the indicator bulb to light. Then the cycle repeats. Nothing to it
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Daily driver: '69 Baja owned 45 yrs - Plan B: '72 Ghia
Yard Art: 2 Sandrails
Outback: '69 Ghia - '68,'69,'70,'72 Beetle - '84 Scirocco, GTI - Pair of '02 Golfs- '80 Rabbit Diesel
VW Wiring = It's just wires

[69GhiaRat]

Thanks runamoc for the reply. That is helpful but I’m not sure I fully understand.

My turn signal dash light only has one wire going to it, from the flasher relay. I have a four prong flasher relay, one wire goes to the speedo light, two wires go to the hazard light switch and the fourth wire looks to be a brown ground wire.

I looked in the blue book but it shows wiring for the 9 prong flasher relay.
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Richard

1969 Karmann Ghia
1969 Beetle

[bnam]

Did you change your flasher relay recently?

The pilot/indicator lights for our VWs are wired rather uniquely. They are powered in reverse. Normally, the central pin of the bulb is positive while the base surrounding it is ground. But, on these 3 lights (oil, turn, gen) the base is powered by a common source that only has power when the ignition is on (via the #15 terminal).

When the oil system has no pressure, the switch is grounded which in turn grounds the pilot bulb (in reverse thru the central pin) which lights up the bulb.

Runamoc explained how the turn signal pilot bulb works. When the ign is on, this bulb has +12V on both sides so there is no current flow thru the bulb.

If you are not using a VW specific Flasher relay, here's what you should do. I'm assuming your 4 terminals are +/B, L(lamp), P(pilot), Ground. Currently you have the bulb connected to the P terminal on the relay. Disconnect that.
Put a 2-1 terminal on the Lamp terminal and connect the wire that was previously there as well as the wire going to the indicator bulb to the same terminal.

This should get your system working.
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1971 1302LS Convertible (RHD) owned since '74
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1965 Karmann Ghia Coupe - under restoration
1966 Fiat 1500 Cabrio (with 1600 Twin cam)
1952 Citroen TA 11BL