11 replies to this topic

[alhow]

Hi All,

 

I have upgraded all my lights all around to LED on a 1979 998, they all work great EXCEPT..

 

I'm getting something called sympathy flash in my indicators, where If I indicate left it flashes as it should but the indicator on the right gets involved a little bit and tries to light up too. This I have been told occurs when my existing wiring for the warning light (tell tale) transfers sufficient current to the opposite side of my LED indicators to light both sides at the same time which ever way I turn and they act like hazards..

 

I've been advised to remove the indicator warning light bulb on my dash, to break the circuit, and if the indicators flash normally, then I should install a diode kit.- I did this, the indicators work fine, but the hazards do not. (As below scenarios)

 

Installing a 'Diode Harness Kit' is designed to allow current to flow from one direction only and stop the current going where it is not wanted. The idea is to isolate the warning light and provide an earth for it.

 

My question is.. 1) what are the two wires that are going into the tell tale light on the dashboard? a)Green and White, b)Green and Red. 2) Is the tell tale earthed through the unpowered indicator circuit/ how is it currently earthed? - Because I've been instructed to isolate and earth it but surely its already earthed? Im basically struggling with figuring out where to make the incision and install this Diode harness..

 

 

Different Testing Scenarios:

 

Everything connected, with Ignition ON :

1. Test the Indicators = Front Both Flash when indicating left or right. Rear Indicators Flash, but gets sympathy flash on opposite side (ie if you indicate right, left lights up a little bit with each flash)
2. Test the Hazard = Front Hazards Both Light up solid without flashing. Rear Hazards Both show no light.

Everything connected, with Ignition OFF :

1. Test the Indicators = No indicators front or back (likely to be normal, powered by ignition?)
2. Test the Hazard = Front Hazards Both Light up solid without flashing. Rear Hazards Both show no light.

Removed the tell tale bulb, with Ignition ON :

1. Test Indicators = Front and Back indicators all work as they should.
2. Test the Hazard = Front Hazards Both Light up solid without flashing. Rear Hazards Both show no light.

NB: When I click my alarm fob, all 4 hazard lights flash in unison as you would expect, so there is power going to these lights. 

 

 

Alternatively, I think I can change the front indicator LEDs to regular bulbs and the whole issue goes away, but in for a penny in for a pound it would be nice to use this bit of wiring as suggested, now that I've bought it.

 

Thanks

Alex

 

 

 

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[KTS]

The tell tale is connected to both left (green/red) and right (green/white) indicator circuits and is earthed through the unpowered circuit

 

by the look of it, to fit the diode harness you would need to:

• cut both wires to the tell-tale lamp holder.
• connect one of the tails left on the lamp holder (shouldn't matter which) to the black wire section in the kit, and the ring terminal at the end connected to the speedo earth post just to the right of the tell tale
• connect the other tail from the lamp holder to the blue wire in the kit
• connect the two wires that were attached to the lamp holder (i.e. the wires from the loom) to the red wires

An alternative solution to the problem is to replace the common tell tale with a separate lamp for each circuit, move the oil pressure warning lamp to the green lense and use the two orange lenses for the indicators

 

not sure what the issue with the hazards is, but may be a result of the significant reduction in current that LED's draw and the type of flasher/hazard relays you're using

Edited by KTS, 25 August 2022 - 09:44 PM.

[IronmanG]

Ye i had to fit this. Sorted it straight away

[Aria Aradhea]

I've also fitted LEDs (front and side wipac/minispares LED indicators and rear LED bulb replacements and even T10 LED bulb for the binnacle gauge) but the issue I had was hyperflashing. Replaced both indicator and hazard flashers for LED types and the issue goes away.

[Icey]

I made up my own LED panels for our clubman front lights and had to do some rejigging of the circuits as you've found, but I took a different route. I switched the lights around on the speedo so that I have seperate left and right indicator tell-tales.

[alhow]

Ye i had to fit this. Sorted it straight away

Did you fit it the way described above by KTS do you know?

[alhow]

The tell tale is connected to both left (green/red) and right (green/white) indicator circuits and is earthed through the unpowered circuit

 

by the look of it, to fit the diode harness you would need to:

• cut both wires to the tell-tale lamp holder.
• connect one of the tails left on the lamp holder (shouldn't matter which) to the black wire section in the kit, and the ring terminal at the end connected to the speedo earth post just to the right of the tell tale
• connect the other tail from the lamp holder to the blue wire in the kit
• connect the two wires that were attached to the lamp holder (i.e. the wires from the loom) to the red wires

An alternative solution to the problem is to replace the common tell tale with a separate lamp for each circuit, move the oil pressure warning lamp to the green lense and use the two orange lenses for the indicators

 

not sure what the issue with the hazards is, but may be a result of the significant reduction in current that LED's draw and the type of flasher/hazard relays you're using

 

Cheers! Just to double check, Would the alternative solution you mentioned mean taking the left and right wires from the current tell tale, and taking one of those wires and wiring into a separate bulb?

[KTS]

yes - exactly that

 

this type of lamp holder would be needed if going that route

[IronmanG]

Ye i had to fit this. Sorted it straight away

Did you fit it the way described above by KTS do you know?

Probably but classic car led included an instruction note in the pack I think. If I got it right it must have been fairly self explanatory. Sorry it was a while ago

[alhow]

nice one cheers guys I'll let you know how it goes

[alhow]

Wired up as you suggested KTS, works a dream!

 

Now I just need to fault find why the hazards arent working as they should. - 

 

Hazards ON = Tell Tale lights up solid, Front Hazards Both Light up solid without flashing. Rear Hazards Both show no light.

[GraemeC]

The flasher unit for the hazards is separate to the one ofr the indicators.  I suspect the hazard flasher isn't on designed for LEDs and hence there is insufficient load for it to work properly.

 

The silver flasher unit with two connections - will need swapping for an LED compatible one.

Edited by GraemeC, 02 September 2022 - 01:44 PM.