ZX Dash illumination bulbs

Brian Oblivion · Post by **Brian Oblivion** » 23 Nov 2006, 15:53

Does anybody know the size and type of bulbs used in the ZX? (mines a 1993 model). I need to replace them all (only one left) as I can't see the instruments at night. Indicators, brake & the like are ok, its the ones that illuminate the dash.
Ta

James.UK · Post by **James.UK** » 23 Nov 2006, 16:22

Arghh! I threw my old dash (faulty one) away about two weeks ago.. It's been in my shed for 3 years!.. Can't recall what type bulbs were in it though.

If it's any help, I think you can get to undo the speedo cable via taking the top right hand air vent out, and ferkelin carefully around behind the guages, saves a lot of grief.

.

citronut · Post by **citronut** » 23 Nov 2006, 18:28

they are 1.2w capless bulbs,on average when i do these i have to replace about 10 in one go,i find the easyest way to check them is remove one at a time with its holder put a meter across the terminals to check continuaty,if they show to be dead pull them out of there holder gently with long nosed pliers,also if they are going black and the meter still shows there ok replace them anyway,i would buy a couple of packs of 10 to make sure you have enough
regards malcolm

Post by **Peter.N.** » 23 Nov 2006, 23:08

If you find the bulbs difficult to remove, slide a piece of plastic sleeving over the bulb and pull. If its the right size it will grip the bulb. Mains earth sleeving might do.

Post by **RichardW** » 24 Nov 2006, 07:57

I did a detailed post about this a while back, but the forum search (or me!) is not good enough to find it

(nor is Google). I'd just change the lot (you need about 20) - not worth doing the job twice! The best tip I remember is that there is a metal tab at the top(?) of the instruments, and you might need to wiggle the panel past this in order to get enough room to reach in behind it to get the speedo cable off. Ignore the Haynes advice about removing the heater duct - it's cobblers!

uhn113x · Post by **uhn113x** » 24 Nov 2006, 08:08

Mine has had a duff bulb forever. When my box of round tuits arrives, all the bulbs are going in the bin, and some 20p LEDs will be going in instead!

simoncanfer · Post by **simoncanfer** » 25 Nov 2006, 22:26

I can't recommend LEDs in the ZX dash; at least not in certain positions. I have an LED inbetween the tacho and speedo and it is ineffective to say the least...

uhn113x · Post by **uhn113x** » 26 Nov 2006, 07:39

Ah, but why was that, Simon?

As LEDs cover everything fron tiny ones up to at least 5 watt Luxeons like one I have in my torch, surely it is only a matter of finding one that is as bright as the bulb was?

I am sure that a "superbright" LED would cut the mustard.
As I have a meter to measure light, I would use it to match one in my LED scrapbox.

Wonder if new cars use LEDs in the dash? I know they do on the brake lights in the rear windows.

citronut · Post by **citronut** » 26 Nov 2006, 09:40

not just the centre brake lights most new car all the rear lights are LEDs
regards malcolm

uhn113x · Post by **uhn113x** » 26 Nov 2006, 10:42

Cheers, Malcolm; suspected that.

simoncanfer · Post by **simoncanfer** » 26 Nov 2006, 17:17

As it happens I use a 3W luxeon as a bike light

The LEDs I bought seem to be made for illuminating in the forward direction only; fine for warning lights. For general dash illumination there is little in the ZX dash to reflect light to the side.

I don't fancy messing with the dash enough to get an LED lighting solution to work, though I have no doubt it could be done! So for me it's regular replacement of bulbs - at least I can get to them in under 5 minutes now...

Simon

lighteninguk · Post by **lighteninguk** » 26 Nov 2006, 22:53

i tried putting LED's in my zx and they always blew when used in the "backing" light and the headlights posistions of the dash. so in those i recommend normal bulbs!!

I used brilliant white LED's and they did look fantastic behind the standard green markings on the dash as the green was much finer as it was not being lit by a normal yellowish light you'd recieve from a normal bulb. it was just a shame they blew.

The led's i used had inbuilt resistors so they were designed to be used at the cars 12v voltage and were designed for dash illumination.

uhn113x · Post by **uhn113x** » 27 Nov 2006, 07:46

Hi Lightening (or, after the LED fiasco, should that be "lightning" ?

)

If the LEDs failed, then something was very wrong. They should last forever, unlike bulbs. The only way this can happen is if the current rating is exceeded. Typical LED currents are 20-30mA.

I would forget about "12 volt" LEDs. There is usually about 14.5 - 14.8 volts about on a car battery when running. This can go up to 25v if there is a problem on the alternator or if you disconnect the battery when it is running.

For dash illumination, use normal superbright LEDs and work out (or get someone to work out) the resistors based on 15v and half the max current rating. Stick a single 10mfd 15volt electrolytic capacitor across the dash supply in case of spikes.

30 mins work. LEDs typically 30p, resistors 2p, capacitor 10p.

micitroen · Post by **micitroen** » 27 Nov 2006, 10:02

Interestingly, the voltage rating in the Citroen manual for bulbs in the CX dash are 14V!

uhn113x · Post by **uhn113x** » 27 Nov 2006, 11:04

Oh! Bulbs are more forgiving than LEDs, but 12 volt bulbs in a car are exceeding their ratings most of the time; not surprising that they fail.

LEDs are a different kettle of fish; it is the current that is important. The voltage is the LED's owm forward voltage and is typically between 2 and 3.5, hence the resistor.

If you exceed the current rating, they fail by overheating; voltage spikes or reversing them punctures the microscopic junction layer.