How to install a Vac-Boost Gauge by a complete N00b

Discussion in 'SN95 4.6L Mustang Tech' started by kalvick, May 7, 2007.

  1. Hey Folks,

    I am a complete noob here so dont take this as gospel. If any mods want to change this
    for accuracy please do so. also I may not be using the "correct" car terms

    Hopefully I can now contribute something useful to other people after I leeched info from other knowlegable Stang Folks.

    for the record I did no Drilling and no Splicing lines. This is the howto I wrote
    to help you guys out.

    After I installed my Accufab Plenum and 75mm Throttle body I decided I wanted to see
    how much more air I can suck into my engine. Since I didn't already know what my old
    plenum and t/b sucked in I really dont have a point of referance to compare.
    This is neither here or there as I just wanted to mod my car. Now to see how much air
    your sucking in, you are gonna need to get a vacuum gauge. Since I plan of getting
    a supercharger soon I got a Vac/Boost gauge.

    ok so here are the things you need.


    a - some white 12 guage wire
    b - some black 12 guage wire
    c - twist ties
    d - keys for your car - duh
    e - a 2 1/16" vacuum boost gauge (i used autometer phantom series)
    f - some rubber connectors to hook up the vacuum lines to the T's
    g - double crimp wire connections
    h - some black screws to hold the guage pod in place to the a-pillar (not totally necessary)
    and some light bulb covers and light bulb wire set
    i - the vacuum line and little connectors
    j - the 2 pod A pillar
    k - little fuse "add a circuit" mini
    l - electrical tape
    m - pliers
    n - teflon tape
    o - screwdriver
    p - something to cut wires with
    q - wifes kitchen scissors (just because and she is pissed about this)
    not shown - 8mm socket wrench and some plastic engine bay tubing


    Here you can see what came guage is the T connecter a rubber connector and hose.
    you can see between the 2 bolts there is a little brass bead. When the 2 bolts
    compress the bead holds the line in place.


    Here you can see a couple of things I used to not splice or cut wires.
    and the double crimps hold the wires in place. more on this soon.


    Pull out the a-piller


    IN this picture take the black and the white wire and thread it behind the weather stripping


    Using the wire crimps, crimp the light bulb socket to the black and white lines you just put in.
    I used black electrical tape to hold everything together once they where crimped.


    here is what an little Fuse "add a circuit" looks like one 5v fuse came from fuse number 37 from
    the cars fuse box. the other 5v fuse came with the kit. put it all together like so.


    here is the fuse Box. I plugged the "add a circuit" to port 37. The white wire is crimped and
    held together with some electrical tape. the black wire is grounded to a screw behind the fuse box.
    you will need an 8mm socket wrench to get back there and loosen it up. this way the white wire can
    hook over it.

    now you can turn on the lights to your car and the bulb should light up. you can also adjust the dimmer on the bulbs too.

    Congrats you have just installed an light to your cars electrical system.

    NOW we have to run the vacuum line


    I ran the vacuum through the same grommet my sub woofer is hooked up too.
    the other end will poke out underneath the steering wheel inside the car. this grommet is located on the drivers side of the engine bay.


    After fishing the line from under the steering wheel thread it through underneath the weathstripping towards the a-pillar.


    here is the back of the Vacuum/Boost Gauge. the light connects on top and the vacuum line goes on bottom. dont forget to put some teflon tape on the threads to prevent leaking!


    here is the vacuum line and light bulb ready to be all put together. i have a little bit of extra wire to give me some play. you can tuck this into the a-pillar pod and the guage will fit ok.


    OK! the wires and the line are connected to the Gauge! WOOT!!! WOOT!!!!


    Now push the guage into the pod. its a tight fight so just give it a little push. if you ever need to change the bulb or anything it can easily be pulled out. also notice the pointer is a little off. if you rotate the guage a little clockwise or anti-clockwise the pointer will be dead smack in the middle.


    NOW this is the part I am not 100% sure I did right. According to all the posts I read you can tap into a vacuum line anywhere.I chose to plug it into the line near the plenum entrance. I chose this location because it required me to only move an existing line onto the T-connector and not cut into an existing vacuum line.


    Here is the route I chose to connect the line. In this picture obviously is not how I am going to leave it. Its just an illustration of where the line goes from a to b.


    here is a close up of how its all connected together.


    Ok here it is all neat and tidy. I used zip ties to hold the line in place. You may want to use some friction tape to hold the ends of the plastic tubing in place and closed up.


    Well as far as I can tell my car is sucking between 18-21hg of air at idle. During normal driving conditions the gauge moves to about ~10hg. Under wide open throttle the Vacuum goes to 0. So hopefully my car is now giving me correct data.

    Now I have to get my supercharger and then I can see that boost half of the guage get some use

    Please let me know if this was useful and boost my ego ;)
  2. :nice: very good write-up, should help alot of people :)
  3. Ummm the white wire goes to fuse #37 and Black goes to ground.....:nono:

  5. Hey it seems that this thread dropped off the first few pages. im just bumping it, in case people find this useful
  6. I like where you tee'd into the engine vacuum. ;) I tee'd in at a different source, and it's a PITA to check my tranny fluid with rat's nest back there (around the fuel rail jumper hose)!
    Nice write-up. :)
  7. Great write-up - good base for other gauge setups for ppl new to that type of work.

    Question - what are you using the other pod for?
  8. great write up man! Now, what kind of blower is going in? :cool:
  9. I dont know what to put into the second pod bay yet. currently its an empty hole :(

    I was thinking about an A/F gauge and get a pretty light show with it. People say you need to do a wideband to do it correctly. I have no idea where to connect the line anyways. Good pictures detailing where to tap in would help me contemplate doing it.
  10. For AFR gauge, I tapped into the red wire with a black stripe that was found behind the passenger side kick panel going into the PCM.

    This is the wire from the front (passenger or driver, cant remember which) O2 sensor to the PCM. Real easy install, but is a light show without a wideband.
  11. I used your write-up for the boost gauge and I'd say it was excellent and everyone should use it when they install their gauge, even if it is just for the lights on the gauges. That add-a-fuse thing is the best invention ever!

    I am in the process of adding a Autometer Phantom A/F Ratio Gauge. I have looked at prior threads and the best I can find is "There are two options for this hookup as well, again it's the left or right sensors. Locate the PCM, which is above or behind the passenger side kick panel. Look for the 104-pin connector. For the left sensor you will go to pin 87 which is a red wire with a black stripe. For the right sensor you will go to pin 60 which is a gray wire with a light blue stripe."

    I haven't found any pictures of the connector or what wires to hook into though. Once complete, I'll try to post some pictures for you and everyone else.
  12. Great write up, very clean install in the engine bay !
  13. just wanted to say GREAT write-up, really saved my ass today putting in my gauge...

    is black to power and white to ground?
  15. got it going power is white grounded black on fuse box. dont like fuse 37 for the fuel pressure guage as it wont work unless lights are on wierd whats a better fuse position??

  16. great write up. I am installing a vortech soon and was wundering how to do this. you rock dude.
  17. you really are a bad-ass, i appreciate the help, nice writeup!

    woops i just saw that i already posted in here

    use your car manual and plug it into the fuse for the dimmers
  18. Great write-up!!
  19. hey what is that black fitting that you used for the other end of the nylon tube to the boost guage? i wana do the exact same setup, i bout the boost guage used and so it only has the wires, the brass fittings and the nylon tube. and did u have to put a sealent or glue to keep it from blowing out the nylon tube?
  20. they are just rubber connectors for vacuum lines. get a variety pack at autozone for like 5 or 10 bucks.

    as for the technical name, I have no idea ;)