Page 1 of 2

Dash light LED

Posted: 13 Feb 2013, 08:49
by Trunkster
To cut a long story short I have had to change the clocks (speado fuel gauge) as a whole unit. All works ok except for the lights so obviously at night I can’t see my gauges. This appears to be down to a break in the copper tape connecting it all together. I have heard about hard wiring LED lights into the circuit. I have ordered some LEDs from ebay and was going to make up a circuit directly into the headlight circuit so they come on with the side lights. Will I need to wire them in series or parallel are the resistors in series or parallel and would I need an inline fuse or is the old fashioned bullet type fuses in my 1981 van be ok? Does any one have any advise on this please? :ok

Re: Dash light LED

Posted: 13 Feb 2013, 09:48
by ghost123uk
Trunkster wrote:I have heard about hard wiring LED lights into the circuit. I have ordered some LEDs from ebay...

Will I need to wire them in series or parallel are the resistors in series or parallel and would I need an inline fuse

Depends on how you intend to do it. It can be done either way. How did you decide what value resistors to buy ?

It had to be said that if you need to ask the questions, are you doing the right thing in taking on a fairly complex modification of the pod backlights. If you are not comfortable with wiring up LED's there is so much that could go wrong behind that dash unit.

Would it not be a whole lot simpler (and cheaper) to fix what is there now ?

If you do go ahead, you will have to work out how you want to do it. If utilising any of the exiting tracks then parallel would be best because of the common earth track. Then you have to have the right LED's (not high output) and the right resistors for parallel use. Don't forget LED's have to go the correct way around (+ve & -ve) If you are confident you are doing it correctly, no extra fuse is needed.

Nah, I can't see the advantage, I'd fix it ;)

Re: Dash light LED

Posted: 13 Feb 2013, 10:35
by Dazco
id be tempted to fix the ribbon thingy, can you see where its broken? i fixed a break in mine by just jumping the break with a bit of wire soldered on either side, was a bit fiddly but easily doable :ok

Re: Dash light LED

Posted: 13 Feb 2013, 11:48
by Trunkster
There is a link posted by cov kid and in it you type in the LED and it gives you the resister you need. I havnt done it yet as the LEDs havnt arived yet. I can see the break in the ribon si I might try the repair first. I thought LED circuit wouldnt be that difficult. Must investigate a little more! :)

Re: Dash light LED

Posted: 13 Feb 2013, 20:26
by CovKid
For the dash lights you can get replacements in LED form in same holder type (Or so I gather) but as I hardwired my dash (got fed up of the ribbon breaks), i just used a silicon sealant to hold them in place. I didn't bother feeding into the original circuitry - just took the power from the headlight switch - much easier.

Re: Dash light LED

Posted: 13 Feb 2013, 21:24
by nevill3
changed my dash lights for LED ones that replaced the old bulbs, see my post here
https://club8090.co.uk/forum/viewtopic.p ... y#p7747350

The fitting I requested was B8.3D this is the same as already fitted to your dash.

Re: Dash light LED

Posted: 13 Feb 2013, 23:34
by ScienceBoy
Nice. And that central pod IS supposed to illuminate!

Re: Dash light LED

Posted: 13 Feb 2013, 23:44
by donciuz
Thanks. This is useful information if you want to keep things original. I don't want to solder the leds into the ribbon. Now just to decide the colour....

I would also like to change the bulbs in the switches as well. Could you point me in the right direction what standard are these?

Re: Dash light LED

Posted: 14 Feb 2013, 06:24
by ghost123uk
This website HERE will supply all the info you need to work out what resistor to use for various series and parallel configurations.

If you use the correct resistor there is little chance of the circuit burning out (as you mentioned in the pm).

You also mentioned trying it all out with a spare dash and a battery, this is a good idea and can be done on the kitchen table in the warm and dry :)

Personally I would use series wiring because the wiring is simpler.

You mention that you would like to use more LED's for places other than the main dash, I would keep those as a separate circuit, again putting those LED's in series with a resistor based on what the calculator on that website indicates.

Re: Dash light LED

Posted: 14 Feb 2013, 08:22
by Trunkster
Thanx John. Just tried out the link for calculater and looks fairly simple. Will try Maplins and see if I can get some resisters and post some pictures! :D

Re: Dash light LED

Posted: 14 Feb 2013, 09:21
by ghost123uk
Tip = Get some thin 2 core wire, like the stuff they supply for use with normal car speakers. Then wherever you want an LED, cut just one of the 2 wires and attach (with solder and thin shrink wrap = Maplins) the LED in, (the right way around ;)) onto the 2 cut ends. Then at the end furthest from the supply, just attach the resistor (solder and shrink wrap ;)) to the 2 ends. Then the other 2 ends of the wire go to the 12V supply (the right way round ;)). This makes wiring them in series easy and neat.

Note, if you wire any / all of them the wrong way around, they won't burn out or anything, they just won't light up !
Practice on the bench (kitchen table) with a spare battery. No need for the dash bit until you are happy you have got it "right" :)

btw, just in case, don't think a battery charger would be easier than an actual battery, it is not recommended as a power source (only as a battery charger ;)).

Re: Dash light LED

Posted: 14 Feb 2013, 11:23
by Trunkster
OK thanx. Just been to Maplins an 29p each for the resisters. Going to have a play tonight so watch this space. I do have a spare batery by the way not a charger! :ok :D

Re: Dash light LED

Posted: 19 Feb 2013, 00:18
by ScienceBoy
I just used 470 ohms generally for mot colours. The LEDs are superbrights and much brighter than the incumbent bulbs, so a little excess resistance is fine. After the weekend I have dimly illuminated hazard switch (too many times trying to find that on a dark night) and an illuminated light switch.

Next step footwell lights and high level, both very focused as you can be with LEDs. Then work on the fog light switch which is tricky as there's not much space through with the existing rear fog on telltale. Oh, and a front fog telltale for when I install those. :lol:

Re: Dash light LED

Posted: 19 Feb 2013, 09:08
by Mocki
Frankly I found I very much easier to buy from eBay the ready resistored LEDs if you can wait to do it. Cheaper and all you have to do is connect the supplied tails of wire to the supply.

Re: Dash light LED

Posted: 19 Feb 2013, 10:11
by Dazco
I bought a pack of 50 ready made up with resistor and tails for a couple of quid, easy peasy.
Do a search on e bay for em , ive looked but no longer have the supplier details :ok