this is how I got my Std Boost gauge working again...
firstly you need the 4 std wires from the pressure sensor to be left hooked up to there std loom points at the Stock ECU location.

the four wires are
BR/W: 5V reference in
G/R: Signal out (some could be BW/R)
B: Ground
B/W: 12V in

the 5v that used to come from the ECU can be sent from a regulator.. this cost me $1.40 to make using a ZV-1539 5v reg and a 1N4004 Diode wired as per pic.
https://www.rx7club.com/forum/attach...postid=1812738

just hook the 12V to anything switched and the 5v out put to the Br/w wire from the Sensor.

the Black ground wire was tapped into and re grounded.. the wire going to the sender and into the loom needs to be grounded, not just the sensor side.
ands that's it! too easy!

 

Good info there Adsy!
Why don't the workshops do it when it is so simple? Hopefully the S5 is identical.

 

jmes i know!! it really takes a few mins to do..
the S5 will be the same or somthing very close i would thnk.

 

Well, the stock boost gauge is pretty inaccurate, so it's probably a why bother thing.

 

yeah i know what you mean, but it looks pretty crappy having a dead gauge!! I really have no need for a boost gauge.. the hand set has one use that for setting up ect.. and done...
i would prefer to watch the road when on full boost myself lol