Dim indicators at rear - Spiyda / Lucas lights

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amulheirn
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Dim indicators at rear - Spiyda / Lucas lights

Post by amulheirn »

Hi all,

A bit of an odd problem here. I was told by a club member that one of my tail lights wasn't working, so I checked it out. At the time of testing, both tail lights worked well and the brake lights too. However the indicators are dim. These are Lucas lights with the Spiyda LED module installed in them. At the front, the indicators seem full brightness, and these are still incandescent bulbs. When indicating, the petrol pump's note rises and falls perceptibly but that doesn't seem to affect fuelling.


Naturally thoughts turned to a bad earth at the rear of the car. However because the side and brake light share a common earth with the indicator and seem to be behaving normally, we discounted that.

Measuring the voltage coming out at the rear seems to show only ~5.9v which seems low. At the front, the measurement is also low, but slightly higher at about 6.5v. Measuring the cable to the rear indicator (green/white or green/blue from memory) at the multi-pole plug under the dash also shows a low voltage.

This is odd because I'd have thought LEDs simply wouldn't light on a too-low voltage, whereas incandescent bulbs would be dim. I seem to be getting the opposite effect, so I'm confused.

After sleeping on it for a while, I am wondering if there could be high resistance in the indicator stalk causing some sort of voltage divider effect. The stalk is one I got from Gerry and is (I believe) the more expensive VW reproduction type. Could the contacts within it have become tarnished or something? I plan to have another look on Wednesday night if I have time.

Just wondered if anyone had any better theories and what people's experience with this kind of indicator stalk is. Is it reliable, can it be dismantled, does it need some contact spray occasionally etc.

Cheers,

Andy
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clive
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Re: Dim indicators at rear - Spiyda / Lucas lights

Post by clive »

What fuse box do you have? If it is the canoe type, I would suggest putting it in the bin and fitting a blade type similar to one of these. Ihad several issues with canoe fuses not giving a good contact and causing voltage drops.

https://www.halfords.com/tools/fuses-el ... h6EALw_wcB
Cheers, Clive.

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peterc
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Re: Dim indicators at rear - Spiyda / Lucas lights

Post by peterc »

Hi Andrew,
I cured my rear light poor performance by adding a separate earth from battery to the scuttle framework. This followed your revelation of weird things happening when wiring up your car until you endured the frame was well earthed.
Do you have any other symptoms like the red charging light starting to illuminate.
Did the lights work well when first installed?
If so then faulty connectors must be the problem.
Peter C
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amulheirn
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Re: Dim indicators at rear - Spiyda / Lucas lights

Post by amulheirn »

Thanks chaps - yes you might be right Clive.

To date I haven't had the energy to replace the fusebox, and was hoping for the best. I even bought some genuinely ceramic ones so they don't melt if contact is poor, but you're right - the blade type is what I should go for.

I'll investigate further.

No other strange lights on the dash Peter. We did suspect the earth for a bit, but testing again elsewhere on the car produces the same voltage. And the rear brake and side lights seem bright, so we're thinking that the common earth they share with the rear indicator is good. I earthed on both sides to the chassis, so hopefully that's not it!
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Re: Dim indicators at rear - Spiyda / Lucas lights

Post by stu60 »

Juts a thought....presumably easy enough to test if its the fuse box by bridging (temporarily!) the appropriate fuse connections with a wire and checking bulb brightness?
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peterc
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Re: Dim indicators at rear - Spiyda / Lucas lights

Post by peterc »

Its interesting if you have the canoe type fuses as I thought that design had been superseded. My fuse box supplied in 1998 is the blade type.
Peter C
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clive
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Re: Dim indicators at rear - Spiyda / Lucas lights

Post by clive »

peterc wrote: Tue May 31, 2022 3:35 pm Its interesting if you have the canoe type fuses as I thought that design had been superseded. My fuse box supplied in 1998 is the blade type.
Peter C
Six years later, I got the canoe type!
It really is a simple upgrade. Just remove the wires and fix to new fusebox, then remove old box and replace with new one. If I remember all it needed was one new hole for a self tapper and job done in under an hour.
Cheers, Clive.

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Re: Dim indicators at rear - Spiyda / Lucas lights

Post by amulheirn »

Thanks for everyone's thoughts on this - I bought a blade type fuse holder and am considering installation.

However.... the cause of the problem turned out to be the hazard warning switch. I didn't realise it (because I never got a wiring diagram for the loom) but it seems the hazard switch is in series with the indicator stalk.

With a bit of measuring in various places, it seemed as though we were losing 3 volts across that switch. It is a Durite item. By chance I had another one ready to go because the original's central red plastic bit with the triangle on had popped out ages back. So we swapped it in and service was restored!

Who'd have thought it...

Another question - in the loom there's a link for 'interior lighting'. I've wired it to door-switches that activate footwell lights. A bit pointless it turns out because they're quite dim and it only really gets driven during the day. But if I changed it to power a map-reading light - should I have an inline fuse do you think, or is what comes off the dashboard loom already fused?

Andy
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Re: Dim indicators at rear - Spiyda / Lucas lights

Post by peterc »

Does the fuse box (or pages of wiring connections) not advise what items fuses cover.
Peter C
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