Dash LED recommendations

[Plan B]

Whilst I have the dashboard out can anyone recommend a source of coloured LEDs for Griff instruments? Prefer polarity independent bulbs.

[TVR-MADS]

Tina at TVRSSW and Paul at Paul Smith have them.

[Mr.Grooler]

Plan B, did you get some (which ones?) and what do you think?

My dash is out at the moment and while I’m happy enough with the standard old 2w bulbs I’m looking at them thinking one of them is bound to blow within a few mins of driving with the dash back in.... So if I’m going to change them I might as well fit LEDs. Thanks

[Penelope Stopit]

Here is a diagram if anyone feels they must have an LED as an alternator warning light

Using Tyco VF4 series 12 volt 40 amp Relay or one of similar specification

Tyco VF4 link - https://www.digikey.co.uk/product-detail/en/te-con...

Coil Resistance - 90 Ohm

Nom Turn On Voltage (Max): 7.2 VDC

Turn Off Voltage (Min): 1.2 VDC

---

Although the above is named a 12 volt relay its operating voltages are wide apart from 12

12 volt relays have carried on working without problems after withstanding 18 volts for several hours when a vehicles alternator has been overcharging

As can be seen above, the Tyco VF4 series will pull-in at approx 7.2 volts and hold-in down to approx 1.2 volts

Is important to view the chosen relay's specification if not using a Tyco VF4 series as specifications vary from manufacturer to manufacturer

---

Wiring a 100 ohms resistor in parallel with the Tyco's coil gives

TYCO 90 Ohm Plus 100 Ohm Resistor In Parallel = 47.368 Ohms

Current = 12 divided by 47.368 = 0.2533355 Say 0.25 amps

Wattage = 12 x 0.25 = 3 = Same as the original 3 watt bulb

100 ohm resistor link - https://www.ebay.co.uk/itm/Wirewound-Cement-Resist...

---

Replacing the original 3 watt bulb with the Tyco relay coil circuit gives approx the same alternator field exciter current

The LED is simply switched to earth through the relay contacts

The relay is energised by forward and reverse voltages

Should an alternator diode fail and apply a voltage to the alternator field with engine not running (ignition off), the LED will warn the driver

---

The warning lights and gauges circuit's show how the relay earths during a reverse voltage condition with ignition turned off (circuits have been simplified)

[blitzracing]

Penelope Stopit said:

Here is a diagram if anyone feels they must have an LED as an alternator warning light

Using Tyco VF4 series 12 volt 40 amp Relay or one of similar specification

Tyco VF4 link - https://www.digikey.co.uk/product-detail/en/te-con...

Coil Resistance - 90 Ohm

Nom Turn On Voltage (Max): 7.2 VDC

Turn Off Voltage (Min): 1.2 VDC

---

Although the above is named a 12 volt relay its operating voltages are wide apart from 12

12 volt relays have carried on working without problems after withstanding 18 volts for several hours when a vehicles alternator has been overcharging

As can be seen above, the Tyco VF4 series will pull-in at approx 7.2 volts and hold-in down to approx 1.2 volts

Is important to view the chosen relay's specification if not using a Tyco VF4 series as specifications vary from manufacturer to manufacturer

---

Wiring a 100 ohms resistor in parallel with the Tyco's coil gives

TYCO 90 Ohm Plus 100 Ohm Resistor In Parallel = 47.368 Ohms

Current = 12 divided by 47.368 = 0.2533355 Say 0.25 amps

Wattage = 12 x 0.25 = 3 = Same as the original 3 watt bulb

100 ohm resistor link - https://www.ebay.co.uk/itm/Wirewound-Cement-Resist...

---

Replacing the original 3 watt bulb with the Tyco relay coil circuit gives approx the same alternator field exciter current

The LED is simply switched to earth through the relay contacts

The relay is energised by forward and reverse voltages

Should an alternator diode fail and apply a voltage to the alternator field with engine not running (ignition off), the LED will warn the driver

---

The warning lights and gauges circuit's show how the relay earths during a reverse voltage condition with ignition turned off (circuits have been simplified)

Really Penelope, don't you ever give up? This has been done to death- NO ONE wants to add a bl*ody relay and a load of extra wiring to the back of a TVR dashboard, just to make a light go out cleanly. Stop trying to show the world how clever you, no one is impressed.

[Mr.Grooler]

Thanks Penelope, however I’m not looking to change the warning lights, just the instrument illumination (my Griff has a total of 9 “BA9” 2w bulbs). eBay and other online places have loads on offer, but many are over-flush so won’t push into the instrument, and I don’t know whether you will get the right spread of light or if they’re too directional.

I have found a few threads on here on the same subject (mostly Cerberas it seems!) but they’re old enough that the links no longer work. Thanks

[lancepar]

Here is one thread..............Have a read.

https://www.pistonheads.com/gassing/topic.asp?t=18...

Basically it depends on the colour of the instuments dials in your Griff'.........black, early or white, later. LED's didn't suit mine with the black dials.

Also with such a low wattage of the incandescent bulbs the failure rate I would have thought would be rather low. I just replaced the bulbs with new green sheaths.

[Penelope Stopit]

Mr.Grooler said:

Thanks Penelope, however I’m not looking to change the warning lights, just the instrument illumination (my Griff has a total of 9 “BA9” 2w bulbs). eBay and other online places have loads on offer, but many are over-flush so won’t push into the instrument, and I don’t know whether you will get the right spread of light or if they’re too directional.

I have found a few threads on here on the same subject (mostly Cerberas it seems!) but they’re old enough that the links no longer work. Thanks

Ok then

Leaving the warning lights alone is a good decision

lancepar has now posted a good topic

Yes LED's being directional do seem to be a problem, where there's a will there's a way

Good luck in getting the job sorted

[rigga]

rigga said:

Penelope Stopit said:

Bye bye

I wish it was, but unfortunately you'll be back.

Well that didn't take long, as predicted ........

[Mr.Grooler]

lancepar said:

Here is one thread..............Have a read.

https://www.pistonheads.com/gassing/topic.asp?t=18...

Basically it depends on the colour of the instuments dials in your Griff'.........black, early or white, later. LED's didn't suit mine with the black dials.

Also with such a low wattage of the incandescent bulbs the failure rate I would have thought would be rather low. I just replaced the bulbs with new green sheaths.

Thanks lancepar, I hadn’t found that thread. The more I read the more I think I’ll just follow your lead and replace the bulbs with new standard ones! I like the colour and brightness, so LEDs would only be for durability. I guess mine have been fine for 14 years!

[David Beer]

I did my griff with white leds, looked fab. I made mine, rubber bung from the rear of a car stereo so you can adjust the depth of the beam. Just slide the bung in or out. Most leds run around 25-30 ma so a single resistor around. All available from RS . From memory the speedo and rev has two apertures.

Edited by David Beer on Sunday 19th July 17:16

[indigochim]

I bought a load from Aliexpress that looked like these
|https://thumbsnap.com/C7PuUv3F[/url]
They where too long to fit so I filed the tops off which also helped diffuse the light. I'm happy with the level of light they give off however I foolishly chose blue LED's which aren't the best for night vision. I'll be swapping to white/yellow next time I take the dash top off. I also switched all the bulb holders for those dials that took w5w push ins to BA9S's so that all the bulbs matched.