MD993

So, I just got my car back from my mechanic who was replacing the fan/alternator bearing due to metallic noise from a failed bearing..
I gave him the instructions on how to remove the fan/alternator assembly and explained to him to disconnect the battery while working on the alternator..
My fan bearing was replaced and my car ran great... until I noticed that the 993 trip computer was very dim..

Something probably went wrong when he disconnected/reconnected battery... or he used battery booster or something maybe..

The trip computer works, but is very dim during day time... At night when I turn on the lights, the rev meter is nicely lit, but the 993 trip computer is still very dim..

Of course I did my research and came to the conclusion that a) the 0,9W blue bulb: Porsche part # 964 641 920 00 is burnt , or b) the N-Channel FET transistor: BS170 needs to be replaced...

After research I will certainly remove steering wheel and airbag to make space to remove the Rev counter...

Before I proceed with ordering parts, which do you think has failed the blue bulb or the transistor..

The 993 trip computer works, no flickering, just dim day and night...

Thanks !!

Foxman

Good thread Here

As Tore notes, with a bit of patience you shouldn’t have to remove the steering wheel. The part numbers for the bulb and transistor are also noted. Good time to replace both.

Good luck!

Chuck W.

I had the same issue and replaced the bulb with a B8.4d-W LED bulb from SuperBright. Very easy DIY. No need to remove the steering wheel.

Here is a post from Tore.

https://www.bergvillfx.com/categorie...obc-tachometer