[Parenn911]

If isn't one thing, it's another . I had a problem with my tachometer where the needle would stick, so I picked up a nice SC tach in Hershey for $40. I replaced it a few days ago, but didn't drive the SC at night until today. I noticed that all of my guages lit up except my tachometer. I removed the tach, switched the bulb with the bulb from my oil/temp guage, but the bulb from my tach worked in the oil guage. So I know it's not the bulb that is causing the lack of light. Could it be the wires? The tachometer lights worked with my old guage. I am not that very savvy with electrical stuff, including deciphering the diagrams. So electrical gurus out there, what is going on?

To top it off, the POS plastic door handle got caught up, and just my luck the thing cracked in half. Looking on the bright side, it gave me a reason to finally order my RS door panels today.

[87turbolook911]

Pari,

If you want to come over I can try to help find the prob. I have a circuit safe Snap On test light.

If we get time I'll test your leads at Auto therapy on Sat.

[APKhaos]

The tach has two lights - one each side. Are they both out??

My guess would be that you have swapped one or both of the instrument lights for the high beam warning light and/or one of the turn signal lights.
Its easy to do.

[Parenn911]

The tach has two lights - one each side. Are they both out??

Yeah Tony, both don't light up. It's wierd because when I put the high beam lights on, the blue dot lights up, as it should.
Thanks Vu, you got a PM.

[Vicegrip]

Check the ground. The tach mounts in a rubber ring and I think has a ground wire.

[Parenn911]

The new tachometer on my 911:

My old one:

As you can see my old one has 3 pins, and my new one has 4 pins. Anyone have a diagram that expains the wiring of SC tachs?
Kurt, do you mean there is a ground wire connected under the rubber ring?

[Jazzbass]

No ground wire in the ring- there needs to be a brown ground wire on the back. There will be a tab on the back that connects directly to the case of the tach.

Give me a call, I'll be wrenching tomorrow. I've got all the electrcial test stuff we need. I also have a spare door handles you can use untill your RS panels come in.

[Parenn911]

Thanks to Vu-gyver , my tach now has light again. It was strange because as the case of the tach was grounded when the lights would be off, but when you turn them on, the case would no longer be grounded. So, Charlie and Vu thought that maybe my new tach doesn't have the wire internally to ground it. Vu fabbed a ground, and now my tachometer has light again.
Here's my tach after Vu did some soldering:

Thanks again Vu.