mmmm, pho FTW!!!!


OP: nice mod and great pics...I can see this being very useful for the right people, or just cool for everyone else

 

Our TL has no place to get a tach signal from. The oem tachometer obviously receives a signal. However, that signal for the oem tach is not suitable for aftermarket devices such as aftermarket tachs, shift lights, rpm windows, nitrous controllers, etc.

Fortunately, many newer cars also lack proper tach signals. Thus, AutoMeter (click here) and MSD (click here) make an electronic device to solve this problem. It is called a Tach Adapter.

Thanks to Acurazine member "jptl04" (OP of this thread), I had a head-start on how to wire a Tach Adapter to my TL.

However, I did not want to splice into every coil wire if I could avoid it. So, I did some research with the TL Service Manual. I discovered that I could splice just one wire under the dash instead of splicing six wires under the hood.








As mentioned by the OP of this thread, it is true that the Tach Adapter must be spliced into all six coils. However as you can see from the wiring diagram for our TL, we can splice into the wire before it branches out into six separate leads.





DIY FOR INSTALLING A TACH ADAPTER







In pic above - Remove the passenger-side console panels to gain access to the ECU area. We will *not* be touching any ECU wires. However, the wire that we do need is located next to the ecu wires.

The wiring harness (and white connector) is actually coming from the fuse panel from the driver-side. In the pics, the harness looks like it is a part of the ecu harnesses. But, it is not a part of the ecu harnesses. It just is routed along the same area.








In pic above - Locate the Black wire with a White strip (Blk/Wht). There is only one wire that is Blk/Wht in the white plastic connector block. However, there are other Blk/Wht wires in the large bundle that it merges into. So, make your splice where it is shown in my pic above, and you will be okay.








In pic above - Soldier the wires from the Tach Adapter to the spliced Blk/Wht wire. Be sure to insulate the connections with shrink tubing to prevent a short-to-ground.

Be sure to soldier these wires. Do not just twist them together. If the connections are lost or unreliable, the engine will not run.







In pic above - Tidy up your work by wrapping/taping the loose wires to the main fat harness.

By the way, the tach signal generated by the Tach Adapter is a true 6-cylinder signal. That is, when you send this signal to other devices (such as aftermarket tachs, shift lights, rpm windows, nitrous controllers, etc.), you will configure that device for a 6-cylinder signal.





PART LIST & PRICES


MSD Tach Driver PN# 8913 = $85 (click here)

 

^^^
you my friend are a genius! I should have looked in the ETM before calling up Autometer and taken their advise. This is way easier. This, and all your very detailed and informative threads should be in the 3rd Gen Garage!

 

Nice job. Looks really clean.

Princely, you mind sharing that information with me as well. I'd like to keep mine looking oem

 

Not at all. What do you need to know? If I can't answer, jptl04 will most likely be able to.

 

WHere did you find the fabric?

 

The fabric was something jptl04 had on hand already, for one of his personal projects. For this, you have to go to a fabrics supplier and try to match the interior color as close as possible.

 

Sorry to dig up such and old thread, but couldn't you just tap into the tach signal wire from the ECU...?

 

From Post#42 above -

Our TL has no place to get a tach signal from. The oem tachometer obviously receives a signal. However, that signal for the oem tach is not suitable for aftermarket devices such as aftermarket tachs, shift lights, rpm windows, nitrous controllers, etc.