Advice on diodes, circuit.. - cluster from car

this.one · Dec 12, 2012

hello everybody

I am new on here so will appriciate any advice

anyway:

I was playin with my dashboard, cluster etc - took it all off... thgouh - I wanted to install some LEDs etc into my cluster and needed to know where do I get positive and negative feed - though:

I connected the side connectors for each oher letf to the right and right to the left socket (interesting is that it got in..! (arrowns point to them)

below is one of the speedo units taken off the board - it has stepper motor and couple of diodes

and all units taken off

and tachometer

now, my question is though - I do not know if it was the reason or not - but - I DO NOT get light into the cluster - 0V in the conectors for bulbs when I turn on LIGHTS on steering wheel -

the only that works on the cluster connected is: OPEN DOOR indicator, LOW BATTERY (I have 9.6V as my car is without engine at the mmt for a while), ANTI-LOCK indicator. thats about contorls. now the CLOCK WORKS, and backlight of them work UNTIL I TURN ON HEADLAMPS - then the clock light turns off... strange, isnt it??!

then - interior lamp works, HEADLAMPS and tailights also...

my question is - could have I damaged the cluster by connecting those two side connectors wrong? :/ (btw no fuse / bulb is blown...

just theoreticaly - WHAT WOULD GET BURNT/BLOWN FIRST - if volts went where they shouldnt ? diodes? transistors?

I did some check on diodes on the board - there are 3 - with my multimeter - had it set up for signal ON for continuity - I get beep only on one diode from those three - though I get some Ohm reading on all of them (they are identical M1 writing - and read 570Ohms or so,,) .. is it correct? or once I do net get continuity beep - it means that diode is blown regardless of resistance reading shown...? or some diodes will do beep (if set to beep) some show resistance reading (if set to OHM reading..?

I can post a wiring technical diagram of the cluster unit - I am not a proffesional so not much of use for me...

JMW · Dec 12, 2012

The idiot lamps will have a common ground, see which side of the the lamps are grounded. If you look at figures 3 and 5, you will see the common trace, this is ground. There may be an additional "data ground", but once it is plugged in and tested they will be tied together. Unless one leg of the diodes is removed from the circuit, the readings are invalid.
If you put volts where they shouldn't be, the most likely outcome will be a burned trace. The other common result is a release of the "acrid, magic smoke".
As for LED lights, they are usually protected, if they don't work, just turn them around. Remember LED's don't respond well to dimmer switches.
If the lights don't work, or do interesting things, you are probably missing a ground. As the engine has been removed, this is probably the case. You may verify the black battery lead goes to a chassis ground. However as the engine is remove the harness which controls all of this is not properly connected. Follow the Hippocratic Oath and do NO damage.

JMW · Dec 12, 2012

Upon reflection of Fig 8. Are you trying to make your own LED's? While this can be done, I think you will be disappointed. An incandescent lamp generates light in 360 degree 3D. Not so with an LED, they have much tighter zones of illumination. I SUGGEST you go to "superbrightleds or some other site and get lamps that plug in directly. It is more expensive, but I'm certain you will be happier. There are usually 3 types of lamps. The illumination and the indicators. Color may be an issue, as if the screen is blue for example a red LED may not shine through. Remember there are NO WHITE LED's. White LED's are actually ultraviolet, doped to give off a pseudo white looking color.

Advice on diodes, circuit.. - cluster from car

this.one

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