badabing

All,

I am about to install the latest generation of LED gauge bulbs which I got from porscheleds.con in my 96 TT with high OBC.

I know from previous experience that these bulbs have to be installed in the correct position polarity-wise to function.

This is not an issue for all gauges except the tach as they just pop out and I can easily ensure that all bulbs in the gauge are lighting.

However, removal of the tachometer requires removal of the airbag, steering wheel, and steering column collar. This obviously requires battery disconnection before proceeding.

So the question is how can I test if the bulbs are installed in the proper orientation in the tachometer without the battery connected or triggering an airbag fault?

badabing

Anyone? Was hoping to do this today.

IXLR8

By going to the Porsche electrical circuit diagram and using a DMM.

Jeff96-993

You can pull the tach without removing the steering wheel. I had to unscrew and wiggle the housing around the column a bit, and it's tight, but it does come out without damaging anything.

deekay911

Use a multii-meter - get the bulb out and switch on the lights - using the MM check which connector in the bulb housing is +ve. Then using some spare wire connect your LED bulb to the battery terminals to detect which connector on the LED needs to be +ve to work..it may even be marked on the bulb if you are lucky.

jo-hans

Same! I just removed the top cover around the column.

badabing

Well, I did end up removing the steering wheel (didn't see the other posts till after, but in hindsight I can see how the top cover removal technique could/would work).

Anyway, in my experience, after disconnecting battery and removing steering wheel and components, I was able to reconnect the battery to test the lights and so long as I didn't switch the ignition on, it did not trigger a fault.

DocTock993

So how do things look with the LED's?
Pics are appreciated!

badabing

im still fiddling a bit. will put some photos up when its all done.