miketf1

i am looking for a wiring diagram for the wiring harness behind the gauges. i want to tap into the tach and thermo. any tips??

also in the "end all sticky" there is a tach wire in for the radio?! can someone elaborate on that?

thanks much, mike

FlBob

Mike,
I read somewhere about the Toyota Tech Info site. It's it
https://techinfo.toyota.com
I did the $10 for one day and downloaded everything I think I will ever need. All the wiring diagrams and how-to disassemble instructions. There's lots of stuff there.
HINT: when you "print" the wiring diagrams it opens them in a pdf file you can save instead of actually printing them.


Bob G

bigpapa

For a good tach signal go to one of your fuel injectors (there should be four) and tap into the uncommon color.

There is no tach wire at the radio. There is, however, a speed sense wire (it's for automatic volume adjustment feature on the radio).

I'm not sure about the temperature wire.

miketf1

thanks bob for the trick! came to the conclusion that there is a serial connection called the CAN. apparently its a common data path among other parts of the car for information to the ECU. no luck there.

i am kinda scared of the idea of tapping into the fuel injectors... if you can kinda explain a bit that would be reassuring.

any tC guys have an aftermarket tach?

thanks, mike

::edit:: ok i am a complete retard. i found the ECM/ECU pinout and it looks like it might be a grey wire for tach and a purple wire for speed. someone that isnt a dumbass like me please verify?

bigpapa

tapping into the uncommon color on a fuel injector (aka the negative side) is common practice when installing remote starters. These wires will provide 1-6 volts of AC signal, perfect for referencing the RPM's of the motor.

I tapped into the uncommon fuel injector for my remote start.