EP91 Wiring up a boost gauge power


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I've just wired up my boost gauge after weeks of putting it off because i could not find a guide, turns out its pretty easy so i took photos to show you how I did it. I have assumed that you have connected the vacuum line to your sensor/gauge, this tutorial is only focusing on how to wire the power, lights, ignition and ground from the back of your head unit.

Tools needed
  • Screw driver (both flat and philips)
  • Wire cutters
  • A way of connecting the wires together, I used connecting block and crimping connectors supplied with my gauge (you can solder the wires if your confident)
Helpful extras
  • Multimeter
  • Automatic cable strippers
  • Spare wire, i got rolls of 5 amp cable from halford for around £3 each. (The cables supplied with my gauge were too short to reach the back of the head unit)
  • Cable ties (keeps everything tidy)

Step 1 - Removing the head unit

To prevent damage to my screen i popped it off first. There may be 2 screws just above the climate controls (mine didnt have any but yours might) remove them if they exist. Then take a flat head screwdriver and carefully pop the fascia off. This takes very little force and wont fully come off at first as u will have to unplug some cables.


Unplug these cables and the fascia will come off


Next unscrew the 4 screws surrounding the headunit (mine are already out in photo)


Pull the headunit towards you, being carefully as to not pull on the cables at the back. I rested my headunit just in-front of the gear stick while allowing access to the cables at the back.


Step 2 - Finding which wires to use and connecting them.

I have an aftermarket head unit connected and the people who connected it butchered my original head unit cables so this made it easy for me to spot the power and ignition cables as they were the only ones they used.

These are the cables you are going to be using


The colours of cables which you will need to use are as follows.

Blue - Constant 12V
Gray - Ignition
Green - Lights


You can see where i have connected the pink crimping connectors in the photo above.

I had to use a black cable from the headunit for ground. Any metal part of the headunit should work as a ground if you are stuck. (multimeter is handy at this point)

Now connect your cables to these using crimping connectors or soldering (i personally think the greddy crimping connectors were really easy to use and meant the cables did not need to be cut) The automatic wire strippers were really handy here for stripping cables without cutting them.

Run the cables to your gauge, i mounted mine on top of the dash at the right hand side of the steering wheel, to access the panel underneath the steering wheel it was 4 screws at each corner.

I used connector block to help extend my cables. The Greddy ones would not reach behind the headunit.


Tidy everything up with cable ties and job done.

Any questions feel free to pm me.
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