Yeah I know
The new SMD's have shown the exact dimmed colour ( light purplely white )
that the Canbus bulbs I used previously did.
Im hoping that its not a current issue somewhere further from the cluster i.e
part of the wiring loom behind the dash.
As you have said, I'm going to check the voltage on the battery and then on the tracks right where the bulb holder points touch, if there is any difference in current then we will know if thats causing the issue ! following that ill unplug and plug back the unit in.
This isn't an easy one for me as I have no Knowledge in electronics at all,
I didn't think the JDM turbo imports had the Dimmer ?
if it did then surely that would make sense.
let me know about your cluster and ill get the voltage checked.
thanks
jordan.
[Mk2] [Turbo] 501 LED dash bulb LED issues.
Moderators: IMOC Moderators, IMOC Committee Members
Re: [Mk2] [Turbo] 501 LED dash bulb LED issues.
I don't think the JDM turbo ever came with a factory fitted dimmer, but I thought I'd better raise that as a possible issue in case a previous owner had done a mod.
I've just checked my spare cluster, and as far as I can see the backlight + and - feeds simple go straight from the middle socket to each of the four lamp holders, so it seems as though it can only be a voltage drop due to a bad connection somewhere.
I've marked the two feed connections to make it easier to get a voltage reading for the circuit (they are either side of the plastic one way key), and will have a look at the wiring diagram later to see if that offers any other clues.
Paul
I've just checked my spare cluster, and as far as I can see the backlight + and - feeds simple go straight from the middle socket to each of the four lamp holders, so it seems as though it can only be a voltage drop due to a bad connection somewhere.
I've marked the two feed connections to make it easier to get a voltage reading for the circuit (they are either side of the plastic one way key), and will have a look at the wiring diagram later to see if that offers any other clues.
Paul
Re: [Mk2] [Turbo] 501 LED dash bulb LED issues.
So after getting a volt meter on the battery it rated 12.46,
I then checked the contact points for the bulb holder and got a reading of
12.15, finally as Paul showed me above I checked the feed points from the plug
and got a reading of 12.26.
so clearly there are not feed issues with power which now leaves me completely in the Dark !
any ideas ?
I then checked the contact points for the bulb holder and got a reading of
12.15, finally as Paul showed me above I checked the feed points from the plug
and got a reading of 12.26.
so clearly there are not feed issues with power which now leaves me completely in the Dark !
any ideas ?
BUILD THREAD : http://www.imoc.co.uk/forums/viewtopic. ... highlight=
Re: [Mk2] [Turbo] 501 LED dash bulb LED issues.
LEDs are current driven, not voltage driven (well not strictly true - they do need a certain amount of volts in order to light up, but as you're reading 12V in the dash, that explanation will suffice). While you're showing 12V, it's possible that there's not enough current getting through. If something has shorted out causing the wiring in the loom to partially burnout, it may still allow the voltage through but not the amount of required current - i.e. the wire is acting as a resistor.
Do you have any idea what current is required by each of these LED bulbs? A check of the supplier's website might yield the answer. If the bulbs are for example rated for 1 watt, they will require around 84 milliamps (12V divided by 1 watt = 0.083 x 1000). If your power supply cannot deliver this then they are not going to reach their full brightness.
The way to test this would be to use a multimeter in amps mode (by switching the positive lead into the correct socked - ensure you put it back to volts etc. afterwards) and testing it in series with the bulb whilst it is power up - do not put the test leads across the bulb's terminals, it will short out the connection. I would do this by finding a way to affic some test wires to the terminals on the bulb bracket - maybe by using an empty old socket to carefully wedge some wires in place. I can then use the test wires to hook up the LED out of its socket to test that the connection is good. Once you're happy with that, remove one of the wires from the LED and hook it back up via the multimeter i.e.
Here's a (terrible) diagram to make it easier to explain
Once you have it all hooked up, set your multimeter to read milliamps and see what the current draw is. Note down this result, it should be similar to the specifications but manufacturers have been known to lie a bit about the power output so it could be lower. One way to be sure is to get a 12v DC power supply and hook one of the LEDs straight up to that with the multimeter also in series. See how much current it is trying to draw which will give you an idea of the real rating - ensure the LED is lighting to the correct brightness.
Hope this helps. It is definitely possible to replace the dash bulbs with LEDs I've been running them for the last five years in my MR2 without issue. They're the surface mount types and there are around 10 LEDs on each "bulb".
If you can't make the required current, then I would suspect something is up in the loom or you have a bad connection somewhere. You really need to get this checked out. At best - the already burnt out wires will just burn out quickly and stop working. At worst, the increased resistance will cause them to heat up, potentially causing a fire.
Do you have any idea what current is required by each of these LED bulbs? A check of the supplier's website might yield the answer. If the bulbs are for example rated for 1 watt, they will require around 84 milliamps (12V divided by 1 watt = 0.083 x 1000). If your power supply cannot deliver this then they are not going to reach their full brightness.
The way to test this would be to use a multimeter in amps mode (by switching the positive lead into the correct socked - ensure you put it back to volts etc. afterwards) and testing it in series with the bulb whilst it is power up - do not put the test leads across the bulb's terminals, it will short out the connection. I would do this by finding a way to affic some test wires to the terminals on the bulb bracket - maybe by using an empty old socket to carefully wedge some wires in place. I can then use the test wires to hook up the LED out of its socket to test that the connection is good. Once you're happy with that, remove one of the wires from the LED and hook it back up via the multimeter i.e.
Here's a (terrible) diagram to make it easier to explain
Once you have it all hooked up, set your multimeter to read milliamps and see what the current draw is. Note down this result, it should be similar to the specifications but manufacturers have been known to lie a bit about the power output so it could be lower. One way to be sure is to get a 12v DC power supply and hook one of the LEDs straight up to that with the multimeter also in series. See how much current it is trying to draw which will give you an idea of the real rating - ensure the LED is lighting to the correct brightness.
Hope this helps. It is definitely possible to replace the dash bulbs with LEDs I've been running them for the last five years in my MR2 without issue. They're the surface mount types and there are around 10 LEDs on each "bulb".
If you can't make the required current, then I would suspect something is up in the loom or you have a bad connection somewhere. You really need to get this checked out. At best - the already burnt out wires will just burn out quickly and stop working. At worst, the increased resistance will cause them to heat up, potentially causing a fire.
Re: [Mk2] [Turbo] 501 LED dash bulb LED issues.
It it would be worth testing a few bypasses from the main feed i.e. battery to the fusebox. Be careful and check the wiring diagrams first though to ensure you keep the appropriate fuses inline - if you're not at all sure I'd definitely take the car to an auto-electrician. Also make sure you use decent thick cable at least as thick as the original wires. Under no circumstances go thinner.