Led bulb problem with new dash

[Meatball]

After fitting new new alloy dash i thought i would fit some led bulbs as the standard ones are a bit yellow and dated. the problem is as per photo some work and some dont??? ive tried turning them around to reverse polarity...and all the bulbs are working if i switch them around...??
The bulbs look blue but are actually white
Any ideas

[spend]

Meatball said:

...ive tried turning them around to reverse polarity...and all the bulbs are working if i switch them around...??

Try removing some of the working ones and see if the non working ones spring into life..

Dave

[richy759]

How have you connected the LEDs? are they just connected to 12v and GND? You have to make sure you have current limiting resistors to stop the LEDs blowing.

Rich

[MADMAX2]

Ahhhh theres your problem....... you are still listening to Radio 1!!!!!!!!!

[Meatball]

spend said:

Meatball said:

...ive tried turning them around to reverse polarity...and all the bulbs are working if i switch them around...??

Try removing some of the working ones and see if the non working ones spring into life..

Dave

I did try that but no luck

[Meatball]

richy759 said:

How have you connected the LEDs? are they just connected to 12v and GND? You have to make sure you have current limiting resistors to stop the LEDs blowing.

Rich

Yes they are a straight replacement to the standard bulbs -
whats puzzling me is why some of them work and others dont????

[richy759]

so they were sold as a straight replacement or you have put them in as a straight replacement?

If you just use standard 5mm LEDs off the shelf they will need to have resistors added in series to stop them drawing too much current and blowing. If they are advertised and designed specifically with the application in mind they will have thought of this and made them so you can just replace the bulbs with them.

Have you tried swapping a working LED with a non working one?

Rich

Edited by richy759 on Saturday 29th March 16:32

[Meatball]

richy759 said:

so they were sold as a straight replacement or you have put them in as a straight replacement?
Have you tried swapping a working LED with a non working one?

Rich

They were sold as straight replacement and ive tried switching them around.
Im waiting to hear back from the company i brought them from..

[richy759]

very odd behaviour
Do they all run off the same 12V feed?
can you look at the voltage accross the terminals on the working and non-working ones to see if there is any difference?

Rich

[Meatball]

richy759 said:

very odd behaviour
Do they all run off the same 12V feed?
can you look at the voltage accross the terminals on the working and non-working ones to see if there is any difference?

Rich

Rich
Will take a look tonight
Cheers

[spend]

Should all be on the same circuit, hence my question..

Dave

[richy759]

spend said:

Should all be on the same circuit, hence my question..

Dave

exactly, Should, hence my question

Rich

[Meatball]

Ok folks your both right they are all linked together...
I tried spends idea again with no luck

whats next..

[AlexanderV8]

I don't know how the circuit is connected, series or parallel.

It sounds like if you are sure ALL LEDs work in the working dial positions, the circuit could be series/parallel. i.e 2 paralleled banks of 2 or 3 LEDs in series. This would mean that if an LED blew, it would only take out the other ones connected to it in series but the other paralleled cct. would be unaffected.

If this is the case, what you may have could simply be an open circuit or a loose wire to one half of the circuit. Either that or one duff LED in the half of the cct. which is out.

Good luck,

Mick

[spend]

The positives & negs are all crimped together in the loom (parallel), if a bulb works in one holder and not the next, then I could only surmise that it is not making proper contacts in that holder.

These are 12v LED bulbs, there should be no need for resistors, or wiring them in series... all that is designed into the component.

Dave

[nia198]

Could the sockets be making bad contact with the replacement "bulbs"? If the voltage is the same at all sockets and the new LED bulbs all work ok in some sockets then it suggests to me that either the polarity is wrong (which you say is not the case) or that you are not getting a proper connection to the new bulbs in the ones that don't work. Alternatively, I don't know how what tyoe of sockets these are. Is it possible that by putting the new bulbs in the opposite way around that the polarity is not actually being reversed electrically? If the bulbs have a central pin for one terminal and a sheath around it for the other then rotating it wont change the connections.

Nick

[Meatball]

Thanks for your ideas chaps im gonna try switching the bulb holders over tommorow and see if i get any joy other than that im stuck

[chrispitman]

I was just about to order some for my dash, can you tell me where you got them from a what ones you ordered.

[chr1sb]

chrispitman said:

I was just about to order some for my dash, can you tell me where you got them from a what ones you ordered.

Ultraleds.co.uk can supply.
Not used them myself, but been to the web site. Expensive, though still cheaper than Maplins.

Chris

[Meatball]

chrispitman said:

I was just about to order some for my dash, can you tell me where you got them from a what ones you ordered.

Chris,
Im gonna have another bash at getting mine to work this week if no joy you can have my led`s and i`ll stick the standard bulbs back in.

If you cant wait your need BA9`s x 5 and 501 capless x 2 all bulbs are 4 bulb led`s you can buy them on ebay for about £12 - £15

Cheers Ben