Hot gauges

[rulloyd]

Hi all

For the 1st time, I noticed my temp / fuel/ petrol gauges outer faces are getting very hot.

I have recently rewired the car which includes modern w5w bulbs.  I also put on a new voltage stabiliser.

is this normal please?  I don’t recall noticing any heat radiating from these gauges before.

thanks for any advice

Rich

GT6 mk2

[johny]

Well the gauges have got a little heater element in them but this shouldnt produce enough heat to warm the outer face. What is the voltage to earth of the stabilser supply to the gauges (light green wires)?

[rulloyd]

11 minutes ago, johny said:

Well the gauges have got a little heater element in them but this shouldnt produce enough heat to warm the outer face. What is the voltage to earth of the stabilser supply to the gauges (light green wires)?

Ok, that means grovelling on the floor…. I’ll check tomorrow.  Thanks Johnny.

[Pete Lewis]

5 w panel bulbs are too high    use 2-3 watt max  might be worth a voltage check     did the old bulbs go black ???

pete

 

[johny]

On 15/11/2024 at 15:06, rulloyd said:

Hi all

For the 1st time, I noticed my temp / fuel/ petrol gauges outer faces are getting very hot.

I have recently rewired the car which includes modern w5w bulbs.  I also put on a new voltage stabiliser.

is this normal please?  I don’t recall noticing any heat radiating from these gauges before.

thanks for any advice

Rich

GT6 mk2

Yes, are you sure you mean w5w bulbs as this is one and I think it would need a change of bulb holder🤔 

[rulloyd]

Hmm.  W5W was based on the replacement needed for the demister indicator which was a direct replacement of the blown bulb (which came with teh loom and was 6W).  Pretty sure new looms come with modern bulb holders for these style of bulbs.  The old bulbs are long gone.   I haven't had the chance but I'll wip out central section of the dash to check the bulbs which will also make it easier to access the voltage stabiliser. The new stabiliser screwed on upside down (in comparison to the original) so it's quite possible I wired it wrong!

Edited November 17 by rulloyd

[rulloyd]

From Autosparks website. Although the replacement loom came from Autosparks, I can't recall if they actually provided the bulbs or how the one I replaced came to be 5W, but I'd better check the rest! (with the exception of the 5W demister bulb, the panel lights certainly aren't bright). 

Due to the unavailability of many of the original metal bulbholders, plastic replacements are fitted which take a modern capless bulb. 

The common replacements that we use are:

Replacement holders for a BA7S 12V 2W panel & warning light bulb take a 12V 1.2W capless bulb 

Replacement holders for a 12V 2.2W panel bulb take a 12V 3W capless bulb 

[johny]

That will explain it and you can always go to LED if you want more light without hot gauges😁

[rulloyd]

9 hours ago, johny said:

That will explain it and you can always go to LED if you want more light without hot gauges😁

Ah, ok.  So you think these capless bulbs run hotter?

[johny]

The originals were a 987 bulb of 2.2W and as far as I can see w5w means wedge fitting 5w bulb so more than doubling the heat output of the design - with incandescent bulbs the energy used is mostly in the form of heat hence their low efficiency. However it does look like wedge fitting bulbs come in lower ratings or even in LED form...

[rulloyd]

Hi all.  Yes, I checked and all my gauges are fitted with 5w which run too hot (probably risking damaging the gauges) so I will change them but being halogen (I presume) they will probably still be hot no matter what watt.  Auto sparks recommend 3w.  The old incandescent were 2w I believe. However, even at 5w the gauges are not that bright.  Is it one of those situations where 5w halogen is the equivalent of a much lower wattage incandescent?

Interested in trying LED which will be cooler  Has anyone with a new loom tried LED for the instruments and can recommend any (capless fitting)?  Most look too wide for the hole in the instrument & also concerned that they may look bright white, not really in keeping with the car.  ‘Warm white’ does not seem to be an option.  501 LED 5w seem to be the ones.

I will steer clear of the indicator & alternator warning lights.

Many thanks. All advice much appreciated.

Rich

[Steve P]

I changed the speedo/ tacho, oil pressure and temp gauges in my Vitesse to led and I think they are a good improvement and not too bright white, and they fit in the same bulb holder.

It was an E bay seller, I will try and find a name.

Steve 

[Iain T]

I've used Classic Car Leds Ltd, he was very helpful in advising me as to wattage and Kelvin.

Iain

[Pete Lewis]

yes used them for panel leds  very good and quick service 

Pete

[Peter Truman]

Be careful some instrument LED's are quite long and can foul the inner instrument workings I had a pressure gauge (if I remember) that suddenly lost pressure after changing to a LED with a lot of side leds, the long fitting fouling the pressure tube.

[johny]

6 hours ago, rulloyd said:

I will steer clear of the indicator & alternator warning lights.

Many thanks. All advice much appreciated.

Rich

No problem with the indicator repeater bulb as this is not involved in the thermal indicator relay operation so can be changed. In fact well worth putting a bright LED in, as I have, to make it more noticeable👍

[rulloyd]

Thank you all, www.classiccarleds.co.uk, Classic Car LEDs Ltd are a really good contact for anybody converting a car to LED.   They are not just suppliers, they research and develop their LED lights.

They recommend a warm white for the 'white gauges' providing 'authenticity' and using coloured LEDS behind coloured jewels.  Using coloured LEDs contradicts other forum advice I've read - but it's obvious that these guys really know their stuff.   They have a blog about this HERE.

They also mentioned that for single indicator warning light installations (like GT6), the LEDs must have dual polarity (which theirs do but most don't).  The alternator warning light can't cope with LED still (or a resister is needed to provide load).  This will be necessary if incandescent bulbs become unavailable of course but I'll bet there's a loaded LED available by then..

For those with capless fittings on your dash loom (typically classic car replacement looms available today, certainly autosparks) the correct bulb (as of today) is part number WVT10WW (HERE) which comes in multiple colours (including pink!).  For the warm white they recommended the less bright 3000k (for the GT6 anyway).   

Good price too!

Again, thanks for all teh advice and help, much appreciated.

Rich

 

[Mjit]

Not sure the logic for NOT using coloured LEDs behind jewels myself.  Incandescent bulbs inherently produce light across a huge swath of the electromagnetic spectrum, certainly from infra-red (the bulb gets hot) through the visual spectrum and the jewel's there to filter that light and only permit certain wavelengths through.  If it's a green jewel only wavelengths of light in the green part of the visible light spectrum come out the other side.  Now if the jewel's going to block everything outside the green spectrum there's really not much point shining light from any other part of the spectrum into it, so it makes more sense to use a green LED than a white one.

I guess the one case would be "The gauges weren't made very well so a lot of white light leaks around the jewel, 'washing out' the green light via the jewel and making a paler green." and that wouldn't happen using a green LED?

[johny]

Also I bought a 'pack' of white LEDs for various dash lights plus spares which worked out cheaper than buying different coloured ones and their spares...

[rulloyd]

37 minutes ago, Mjit said:

Not sure the logic for NOT using coloured LEDs behind jewels myself.  Incandescent bulbs inherently produce light across a huge swath of the electromagnetic spectrum, certainly from infra-red (the bulb gets hot) through the visual spectrum and the jewel's there to filter that light and only permit certain wavelengths through.  If it's a green jewel only wavelengths of light in the green part of the visible light spectrum come out the other side.  Now if the jewel's going to block everything outside the green spectrum there's really not much point shining light from any other part of the spectrum into it, so it makes more sense to use a green LED than a white one.

I guess the one case would be "The gauges weren't made very well so a lot of white light leaks around the jewel, 'washing out' the green light via the jewel and making a paler green." and that wouldn't happen using a green LED?

Yes, that's more or less what Classic Car LEDs are saying in their blog.  Use colour behind colour Jewels.

Edited November 29 by rulloyd