How do I install a shift light

[racecar866]

In my 944 racecar, I want to wire in a shift light. I know how to get power and ground, but where else do I wire it to for the RPM's. Has anyone done this any specifics would help.

[924Sman]

What light are you using?

If you have a red, black and green wires...

Red to the ignition switch

Black to Negative side battery

Green to Neg coil terminal or

to the tach plug connector, IIRC red/green wire but really not certain.

Dal

[racecar866]

I havnt bought one yet, because I was hoping someone could suggest a reasonably priced unit. But going back to your above response, I just wire it to the coil?? Then find power and a ground??? IS that right, because I thought you had to find a wire in the dash somewhere and that was turning me off of installing one...

[Porsche-O-Phile]

Not to sound like a jerk, but what's the point of those things? Why not just look at the tach once in a while and learn the sound/feel of your car?

I don't see much use for 'em. Extra weight.

[VaSteve]

Shift light is in your peripheral vision. In my 944, the tach redline is at the right lower side of the gauge. 911 owners turn the guage so the needle is at the top. When you're doing 100+ with the windows down and a helmet on, even in a noisy 911 you sometimes need the visual reference.

If a light is too much extra weight, take a dump before your run session.

[JivenJim]

This is also on my to do list. Which light did you get?

On pre 85 944's There's a 6 pin plug that is connected to your tach. You could pull this plug and some slack and then splice everything from there.

Tachs Pins:
*1- {Black/Yellow Engine} Speed (ignition) switched +12V
2- {Green or Green/Yellow} Injection Signal (wave) (internal connection to HG)
*3- {Gray/Blue} Speedo Hall sensor (wave signal)*4- {Blue/Yellow} GND , Coolant Temp gauge is feed from this pin
5- {Black Switched} +12V (is internal connection to H+)
*6- {Green} Ignition pulse (neg side of coil)

Or Go Engine Compartment route, previous mentioned.
{Green} Ignition pulse (neg side of coil) Slice Run new green wire from the 14 pin plug (front driver side firewall) from the ONE pin (Fat white or Green depending on model) or be messy and run a wire right to green wire on coil Green wire.

Take a Pic when you finish and let us know if the weight drags down the car much.

[924Sman]

There are a few "light" styles available if weight is an issue. Do you need the tach readout as well or just a single light or sequential lights? Big difference. You get what you pay for when it comes to shift lights. Do want the "RPM pill" style or the adjustable RPM? Do you have aftermarket ignition system? Stack-Stewart Warner are up in the top of the lines. Autometer is popular but generic IMHO have no imput on their stuff. MSD is junk IMHO from having numerous failed ignition boxes and failed "big red" lights.

Yes the negative coil post is all you need. Just be certain the coil is up to snuff.

[onZedge]

Funny, but the MSD 6A I have is on its third car in at least twenty years. Serial #52076 if anyone cares. Autotronics apparently doesn't. I gave them positive feedback on the unit but haven't heard a peep from them since I e-mailed six months ago. I also had a pertinent technical question regarding the validity of the claim that their SCI unit has 36 degrees of crankshaft spark duration for a four cylinder engine (as stated in the on-line O&M manual) versus 20 degrees claimed in all their color brochures. If they had bothered to back up the claim in the manual, I would have bought the SCI unit in a heartbeat and sent them my old 6A for their testimonial museum or something.

Forgive me if I sound bitter, but when I visit a manufacturers website that has words sort of like: don't hesitate to contact us with technical questions yada, yada, yada and I never hear from them, it just pisses me off.

Oh well, life goes on and so does this tangent I'm off on...