Replacement dashboard instrument lights

[Robin]

Looking to replace the instrument lights on my vitesse with LED versions from the club shop. Is this just a straight swap or do I need to do anything else? Some people mention adding relays but is this necessary?

[RogerH]

Hi Robin,

most dash LED's are a straight swap.

Relays are usually fitted to the headlights to overcome volts drop in the long loom.

Roger

[dougbgt6]

Robin,

As Roger says no relays required, in fact they use far less power than filament bulbs.

And, much as I like to support the club shop their LED instruments bulbs are eye wateringly expensive, £10 EACH! the same things are on Ebay for £3 each. I can tell you that they are identical and  just as good as I converted 2 years ago with no problems.

Doug

[Robin]

Great - thanks to both of you for the advice

[Paul H]

Go to https://www.classiccarleds.co.uk/

much better option , as they specialise in classic cars . I’ve upgraded dash lamps , tail , side, brake 

Paul 

[Colin Lindsay]

For dash lights ie oil, full beam etc go for the flat versions that point in one direction only. I can see my blue full beam warning lamp now!

Obviously for gauges you need the ones that shine 360 degrees. I changed all of my GT6 green bulbs to LED white and they look very nice at night.

[Paul H]

These are the ones I bought for my Vitesse 

https://www.classiccarleds.co.uk/products/glb987-e10mes-blue-5-smd-led-bulbs-dashboard-gauge-lighting?_pos=2&_sid=87aa70e25&_ss=r

Recommended

Paul  

[dougbgt6]

1 hour ago, Colin Lindsay said:

I changed all of my GT6 green bulbs to LED white and they look very nice at night.

Sacrilege! 

Even my footwell lights are green. I did try a green roof light, OK for Halloween, but a step too far for everyday.

db 

[Pete Lewis]

another plus for classiccarleds    straight fit and much clearer  much cheaper and reliable 

Pete

[Robin]

On 07/02/2021 at 11:07, Colin Lindsay said:

For dash lights ie oil, full beam etc go for the flat versions that point in one direction only. I can see my blue full beam warning lamp now!

Obviously for gauges you need the ones that shine 360 degrees. I changed all of my GT6 green bulbs to LED white and they look very nice at night.

Hi Colin - where did you get the blue HB led bulb from ?

[Pete Lewis]

i dont think colin had blue led just a  bright white behind the dial Blue jewel

Pete

 

[Colin Lindsay]

1 hour ago, Pete Lewis said:

i dont think colin had blue led just a  bright white behind the dial Blue jewel

Pete

 

Correct! Just the white led shining through the blue glass jewel. Far, far brighter than the old bulb - as I mentioned earlier, it's the one that has a flat end with all of the diodes facing forwards.

[Robin]

Ah - Ok. Thanks Colin & Pete

[Robin]

Have replaced all of the dash lights with led versions and must admit they are much better. The only problem is that the led for the  red ignition light stays on constantly when the engine is running so I’ve switched this bulb back to the original and all is fine. I’m assuming that you can’t use a led replacement for the ignition bulb?

[Robin]

Just now, Robin said:

Have replaced all of the dash lights with led versions and must admit they are much better. The only problem is that the led for the  red ignition light stays on constantly when the engine is running so I’ve switched this bulb back to the original and all is fine. I’m assuming that you can’t use a led replacement for the ignition bulb?

 

[NonMember]

2 hours ago, Robin said:

I’m assuming that you can’t use a led replacement for the ignition bulb?

Indeed you can't. The ignition bulb provides starter current to the alternator so it needs to be of a sufficient power rating. An LED just won't provide enough.

[daverclasper]

25 minutes ago, NonMember said:

The ignition bulb provides starter current to the alternator so it needs to be of a sufficient power rating.

Does this mean if the the bulbs blown or not sufficient, it won't supply the alternator/dynamo to work?.

Cheers , Dave  

[Pete Lewis]

yes that can happen  the circuit senses the voltage

way back when diesels were low rpm and alternators were a bit new fangled we put a 2watt ignition bulbs  in to lower the cut in rpm 

or you were at half revs before the lamp went out 

so dont know about a modern unit but the bulb was important 

Pete

 

[Robin]

12 hours ago, daverclasper said:

Does this mean if the the bulbs blown or not sufficient, it won't supply the alternator/dynamo to work?.

Cheers , Dave  

Dave - thought that might be the case. So if I keep the original filament bulb for the ignition light but keep LEDs for all of the others then that should be ok?

[Robin]

12 hours ago, NonMember said:

Indeed you can't. The ignition bulb provides starter current to the alternator so it needs to be of a sufficient power rating. An LED just won't provide enough.

Thanks Rob

[Chris A]

When I bought a set of LEDs for the same purpose the supplier actually pointed out not to use one on the ignition warning circuit, the set covered all the others.

[Pete Lewis]

some alternators have a seperate sensing lead  often found on  things like vauxhall viva's   (if you can find one)

pete

[Badwolf]

Now you have me worried. I replaced all my dash bulbs on the spit with LEDs about 3 years ago. I'm sure I did the ignition warning as well. No problems up to now. Must go and check.....well, when it gets warmer!!

[Chris A]

43 minutes ago, Badwolf said:

Now you have me worried. I replaced all my dash bulbs on the spit with LEDs about 3 years ago. I'm sure I did the ignition warning as well. No problems up to now. Must go and check.....well, when it gets warmer!!

NO! don't go looking for trouble! Trouble will find you easy enough 😲

[NonMember]

58 minutes ago, Badwolf said:

Now you have me worried

Sometimes you might, maybe, get away with it.

Traditional alternators use a "field winding" on the rotor to generate the rotating field that makes the AC voltage on the fixed windings that passes through the diode pack to charge the battery. The field winding is controlled by the regulator, so that when you don't need much power it just reduces the field strength. It's supplied by a second set of diodes, off the same fixed windings. This is great as long as it's working, but until you've got some field in the rotor there's no power being generated to feed that supply, so no current to create the field. This is where the ignition warning light comes in. It's connected from ignition switch to the top if the field winding. When working, both ends are at around battery voltage, so no light. When stationary (no field supply generated) the bulb has voltage across it, so it lights up, but more importantly it also supplies some current to the field winding to get it started.

Some alternators end up with enough residual magnetism in the rotor armature to kick start themselves. If yours is like that you'll probably "get away with" an LED.

Modern alternators usually have far too much electronics built in and no longer rely on that design. So with one of those you may be OK with an LED too.