TACHO GLOBE REPLACEMENT

[pah]

Guys,

How hard is it to replace the light bulb in the tacho? Mine's blown after 14 years.

And is there an LED upgrade available these days?


PAH

[billwest]

Not difficult, a bit finicky. disconnect cables (speedo, tacho).
I used LED globes in mine. Go to an auto store, and ask for instrument panel globes (push fit), take the OEM one with you.
Do the lot while you're at it.

[BrettZZR]

... Do the lot while you're at it.

This!!

Dunno if I had cheapies or something but if you have "wedge" type bulbs...



...the LED types (mine anyway) fit in either way but only worked one way, so test before you put it all together again.

If you use LED bulbs for the other instrumentation too, you might find that the red lights light rather pink but the high beam blue is the best blue you've ever seen. So if there is a choice go for the lower K numbers, which in a mind-fuckingly contrary logic are often referred to as "warm white"...

(-8

[pah]

Yes LEDs will only work ONE way. LED stands for Light Emitting Diode. And diodes are devices that allow current to flow in one direction only. Current flows only in the direction of the arrow on the diode.

One diode on an AC supply will convert AC to DC. But the reverse current will be lost due to the diode blocking it. Four diodes are wired together in a diamond pattern to make a Full Wave Rectifier that converts AC to DC. VERY ripply DC but it's DC.

I pulled the crappy GMH radio out of my 1982 42L V8 Commodore and installed a Pioneer Cassette Stereo in its place. I connected the old GMH radio to a 12v battery charger to listen to music in the garage. The DC power from the battery charger made the radio too noisy to listen to. I connected an old ignition coil inline with the red lead and I connected a very big capacitor between the red and black leads. These two devices totally suppressed the noisy power from the battery charger and enabled me to listen to the radio.


PAH

[pah]

That diagram stuffed up because it's a GIF. Here's one that should come thru OK.


PAH