[ironhead1230]

I did search through the boost gauge install threads, but I didn't find much specific information for the 08. Most threads are for the 07 and earlier.

I went to install a prosport electrical boost gauge today and have a few questions. First, I was going to tap the clock harness for power and want to make sure I have the correct wires. This is what I found with a multimeter:

Yellow / Red - Acc
Blue / Red - 12V Constant
Brown / White - 12V Ignition

For the prosport, I should only need the Acc and 12V ignition for the gauge itself and the 12V ignition for the sender unit.

Second, I looked for a grommet to get into the engine bay through the firewall, but could not find any. I looked under the pedals in the driver foot well and also in the passenger foot well without any luck. I didn't pull up all of the carpet and sound deadening material so I guess it is under there somewhere. For those that have already installed a boost gauge in an 08 STI, where did you thread the wires through to the engine bay?

Thanks for any help.

-Mike

[sleepyhead]

I recently installed a boost gauge but I did not take any pics but I'm pretty sure you got the right wires. The only issue I ran into is finding a good ground. The clock harness did have a ground but it didn't work for me. I ended up taping the separate ground from the head unit.

In regards to getting through the firewall i went through the passenger side. If you pop the hood and look against the firewall you will see a rubber boot and that is where i passed the wires through. I used a metal skewer to push the wires through (engine bay side into the car) and it was a pain, it helped having a second person there.