VW Jetta TDI LED Boost Gauge
VW TDI "In-Dash" 0 – 25 or
30 psi Boost Gauge Install Guide - By
Justin was a pioneer in getting these gauges
installed mainstream on the VW Jetta
TDI. He spent endless time experimenting, writing, advising with Jetta specific issues, and generally helping with this
great modification. This article is for the most part all his doing. IMP
Concepts has made a few additions and changes with Justin's approval, so we
hope it helps you with your DIY installation experience. This particular
install is specific to VW Golf and Jetta MK IV
platform TDIs.
A special thanks to
Disclaimer (Please Read
it Thoroughly)
By connecting and using this Custom Gauge
you agree that the designer of the gauge and author of this document are in no
way responsible for damage to persons, a vehicle or vehicles as a result of
installing meter.
Liabilities: The author and
designer assume no responsibility for the modifications you do on your car.
Although to our knowledge these instructions are accurate, this includes any
errors that these instructions may contain, any differences between your car
and the one(s) showcased, as well as any errors in following the instructions.
If you don't feel comfortable working with automotive electrical wiring we
suggest you let someone with some experience do these modifications. The
installer should posses a good understanding of the electrical system of the
vehicle being worked on. Please double check all your connections and
ALWAYS work with the car battery DISCONNECTED. Always keep your safety
and that of others as the highest priority.
Warranties: The modifications
described in this document could potentially void any manufacturer's warranty
you may have left on the car (not likely, but possible nonetheless). You assume
all responsibility if your car is still covered by warranty.
Legalities: Laws in your country/state/region/whatever
may not allow you to modify systems such as these on your car, the penalty
being at least a fine. Please check with your local authorities to be on the
safe side.
We also assume NO RESPONSIBILITIES what so
ever for any accidents cause by the driver gazing at this tremendous addition
to the stock instrument cluster while they should be concentrating on the road
and their driving. We always endorse good and safe driving practices at all
times. With that, good luck, and have fun with this Custom Made Gauge.
Complete
Dash with Boost Gauge Mounted in the Car
Tools Required
Tools Required (Highly
Recommended)
· 12V power supply with 2k or 3.3k Ohm resistor to test your LEDs after soldering and installation
Additional Supplies
Required
OK. Let's Get Started
NOTE: For those of you who are having it installed into your complete cluster,
just follow the Blue steps for cluster removal
and the wiring up of your upgraded cluster. For those of you who are having it
installed on to your Tachometer dial and not your whole cluster, follow the Blue steps for cluster removal and the wiring up of
your upgraded cluster, and the Green steps for
dial face removal and reinstallation. For those of you who will be doing the
full DIY version of IMP Concepts Boost Gauge you will need all the steps.
Step 1 - Cluster
Removal
Lower the steering wheel and pull it out as far as
possible. Remove the trim piece directly below the cluster. Fold it back and
lay it on top of the steering column.
Remove the 2 torx screws
holding the cluster to the dash.
Now grab the bottom of the cluster and wiggle it
out. Once the cluster is free, unhook each of the connectors by lifting on the
purple tabs.
our
cluster is now free from the dash. If you plan to send the whole thing into us
for the installation of the gauge (or another installer) then skip to Step 10
when you receive your updated cluster back. For everyone else, keep reading...
Step
Place
Remove the two #15 Torx
screws on the back of the cluster at both ends:
With the small flat blade screwdriver, gently pry out the
locking tabs and insert the stiff plastic shims to keep that catch from
re-locking. Do that to all 6 locking tabs:
You can now pull the back of the cluster out of the
front housing. The small plastic pieces may fly in all directions,
just make sure you don't loose any of them into the tach
mechanism or housing before proceeding. Set the electronics portion of the
cluster guts face up on your work surface and place the front housing in a safe
location for now. You will notice that the tach dial
is a separate piece from the speedometer and other gauges. It is this tach dial that needs to be removed. First mark the position
of the tach needle on the white plastic support
behind the tach dial. This is an index mark so you
can return the needle to this exact position when reinstalling the face of the tach. My tach needle always
stopped at the zero mark but we've heard of others dropping below the zero mark
when the engine is off.
Remove the tach needle by
gripping the needles black hub between your thumb and forefinger, using a
pulling and counter-clockwise twisting motion remove the needle. It may take a
few turns and a good pull to remove it. The first time we did it we ended up
twisting it around two or three times, the second time we got it off in one
pull and about 270° of rotation. We think we were being too gentle the first
time.
Once the needle is off you will notice two notches
at in the dial face around the hole in the centre. You
will also notice two tabs on the white plastic centre post offset from the
notched in the dial by about 45°. You now need to turn the tach
by holding the edges and that tab at the top with the small bar-code on it, and
rotate it 45° counter-clockwise to match the dial face notches with the tabs on
the white plastic centre post. You should now be able to lift the tach dial free from the assembly. Here are two pics showing the dial notches and the tabs on the centre
post:
Your dial face is now free from the gauge cluster.
If you plan to send the dial face to IMP Concepts (or another installer) for
installation, then skip to Step 9 when you receive your upgraded dial back. For
everyone else, keep reading...
Step 3 - Making
the Aluminum Drilling Template
Take your two pieces of 5" x 5" aluminum
(I used ¼” thick plexiglass,
but note that the plexi can not be used as a template
as many times, as the holes will “wear” larger and less accurate each time)
clamp them together and drill four holes in each corner .5" from the two
edges using a 0.25" drill bit drill another 0.25" hole .21" from
the side and 2.71" from the top. Drill one hole in the exact centre
(2.5" from all sides) using a 0.5" drill bit. See the following plan
for detailed measurements (NOTE: You can click the plan image below to download
a PDF of the file to your computer to use as template):
Mark the top and bottom of your template so you
won't mix them up. Insert the the 1" x .25"
machine screws or bolts into the four corner holes from the bottom and attach
the wing-nuts to the top:
Take the paper LED drilling template you
received with your control unit and cut it out around the outside edge and also
the centre hole. Set your bolted together template on to a flat surface and
insert one of your sockets in to the centre hole that fits the tightest with
the least amount of play. put the smooth end into the
other .25" hole you drilled along one side. These will act as guide pins
as you glue the paper template to the aluminum. Using the
glue stick, or white glue. apply a thin coat to
the back of the paper template. When thoroughly coated, carefully set the
template on top of the aluminum template aligning the centre and side holes
with the guides. When you are 100% sure it's properly in place, you can remove
the guides and firmly press it on to the aluminum. Let it dry for the time
specified by the adhesive manufacturer:
Using your centre punch tap with the hammer,
tap the centre point of each hole that needs to be drilled. This will give the
0.067" or # 51 drill bit a good spot to start drilling with less chance of the bit
wandering at start. Don't forget you need to drill a hole along the upper edge
just a bit right of the
After drilling you can remove any burrs or sharp edges with emery paper
or with a larger diameter drill bit on the holes. The inside surfaces of your
template must be perfectly smooth to prevent marring the front of your tach dial. You can also soak the paper template off the
front of the aluminum template with a bit of water or leave it on (we preferred
it off). What we then did was cut another one of the paper drilling templates
out and sandwiched it into my aluminum drilling template. Use the socket in the
centre hole and the smooth ends of the .25" and 0.067" or #51 drill bits in
the other holes to act as guide pins. We drilled this to simulate the drilling
of my tach dial. Checking it after, all the holes
lined up as they should. If they hadn't we guess we would have to make a new
aluminum base and start drilling again. We also took a colour
photocopy of my dial when we had it out of the cluster. We trimmed this colour photocopy out, sandwiched it in the aluminum
drilling template and drilled it. It also came out the way we wanted it:
Step 4 - Drilling
the Tach Dial
Okay, now here is where your palms should be
getting sweaty! You have one chance at this because if you screw up you can't
go down to your local VW Parts counter and buy a new tach
dial face for $10. You either have to buy a whole cluster from them (very
expensive) or buy a used cluster from someplace like an auto-wrecker or eBay.
This is why we took the extra steps in the previous step to ensure my holes
were going to fall in the correct spots and that they were evenly placed.
Double check and triple check everything at this stage to ensure accuracy.
Insert the socket and drill bits you're using as your guide pins. NOTE: the
.25" bit is missing in this picture because it wouldn't stand up on it own
properly and we were afraid it would fall over and scratch the face of the
dial:
Set the top section of the aluminum template on top
of it and carefully thread on the wing-nuts until just firm. Then gradually
tighten them firmer in a circular fashion to ensure even pressure on the dial.
Remove the guide pins and examine the holes to ensure that nothing has twisted
in there.
Now it's time to drill. The Dremel
drill press was very handy for this because we could get it up to a high speed (remember, use a SLOW speed if you use plexiglass!)
and it's light to use. Insert a new fresh built
into the chuck and start drilling the holes:
IMPORTANT TIP FROM THE
DESIGNER: Drill each hole only once, this is important because entering the
hole multiple times can make the hole slightly bigger, causing the LEDs to not fit as tightly and therefore be more difficult
to work with and bond to the back of the tach dial in
the preceding steps.
Remove the tach dial, breath a
sigh of relief that it came out the way you wanted it to and relax now, that
was the trickiest part of the procedure:
Step #5 -
Applying the White Type to the Dial Face
Being a graphic designer by training we had to have the type on my
dial match the existing style exactly. We had done a 400 dpi scan of my dial
previously so we imported it into Adobe Illustrator and used it as a template
to work from. The VW font used is a variation of the classic Futura font that falls between the font weights of Book and
Heavy. We chose to start with the Book weight, set a line of characters that
we'd need and then convert to vector outlines for editing. We then dragged my
outlines over the template in the Illustrator file and started modifying the
characters. Once we had tweaked all the characters to my liking, we arranged
them onto an 8" X 10" area duplicating them to fill up the sheet and
then we emailed the computer file off to a local firm that converts my file
into a dry transfer lettering sheet. You can compare the difference between the
standard futura fonts and my font in the following
sample and compare that to characters on the actual dial. Sure, many of you
can't see much of a difference in the end and think this my
be overkill but we had to do it.
And here a computer generated test of the font on
the dial:
Of course, if all you can find at your local hobby
shop is a sheet of Commercial Script, that could be
pretty swanky too:
When applying the type, start at the top and
working down. I placed scotch “removable” transparent tape in rows across the
dial to help me align the characters.
When applying the type firmly hold
the carrier sheet in position by pressing down in spots on the sheet where
there is no type. Use a smooth tipped tool or a very dull soft pencil. When
burnishing the characters down, only rub the actual area of the letter to
prevent any residual carrier sheet adhesive from transferring to the dial.
After transferring the character, slowly lift one edge of the carrier sheet
while continuing to hold down the other spots, to see if the complete character
has transferred. If not you can drop that one corner down again in registration
and burnish the type further to transfer all parts. After transferring each
group of type, take the backing sheet that came with the type and carefully
place it shiny side down on the newly transferred type and burnish down again
for the best bond; this is a critical step to get long lasting type. The good
thing is if you do make a mistake applying the type, you can use a good quality
painters masking tape (it's the green stuff you see in some of my pictures) and
use the corner of a small piece to pick up the damaged type and then reapply
it. After your type is applied you can hold your dial up to a light to ensure
you didn't place any type over top of the other gauge warning icons: Warning! Don’t press
too hard when transferring the characters. They will deform and distort and not
look good.
What we did at this point was was
cut out a piece of paper a bit larger than the dial and with a semi-circular
window around the LEDs cut out as well. We taped the
dial face down on this to protect it and the newly applied type. We then taped
a few of those flat plastic pieces to that paper to use as spacers (not near
the LED holes or where the type is) and then taped the whole dial face down to
a smooth clean sheet of paper with some of the green masking tape. This will
protect the dial face, the type and allow a clearance for the LEDs to be inserted in the next step. In fact we left it
taped together like this to protect it until we were ready to install it back
into the cluster.
Step 6 -
Inserting and Bonding the LED Indicators
You can now insert your LEDs
into your drilled holes. Remember that you're now working in reverse and that
"0" is on the right and the "20" (or your gauge max) is on
the left. We found that the blue LEDs slipped into
the holes with very little resistance but the reds required a bit more force
though all easily stayed in position when inserted. It's because of this that
we only drilled each hole once as per the important note in step 4 above. If
the holes were any looser you may have problems keeping the blue LEDs in their holes as you work with them. We positioned my
LEDs so the anode lead (the long one) would be on the
inside of the circle:
If you notice in this picture with all the LEDs inserted, we had to twist the ones near the
"20", “40” and "50" to keep them from obstructing the
numeral:
Okay, now it's time to permanently attach the LEDs to the dial face. What you need to do is place a small
dab of caulk between each LED. Only touching the facing sides
between each LED and the dial face. Not along the inside or outside of
the LED circle and not above the level of the plastic LED body. Probably with a
small tube of caulking you can poke a small hole in the end of the plastic
applicator and apply the amount of caulk you need in this step but we
accidentally cut too much off the applicator end without thinking. Therefore we
had to use something to apply the caulk to the LEDs.
It was suggested to me to use toothpicks but we were out and we ended up using
wooden skewers. These actually worked great because we could hold them like a
pencil and they were probably much easier to control than a short toothpick:
You can see in these pictures that we also applied strips
of masking tape to the dial where the dial numbers come close to the LEDs. This will protect them from getting messed up with
the caulking, paint and other stuff. Here's the first step of bonding done:
When this step is dry (4 to 6 hours) you need to add a
very very small amount of caulking around the inside
of the LED circle and a small amount around the outside edge. Let this now sit
for 12 to 24 hours to dry.
Step 7 -
Soldering the LED Indicators
Trim all of the anodes to about 0.5" and the
cathodes to 0.125". We did these at this step but you can also trim the
leads before inserting them into the dial:
Using small needle-nose pliers or tweezers bend all
anodes over 90° to touch the neighbouring LEDs anode. You can also hold the LED firmly with the
pliers and using a small flat blade screwdriver, push the lead over as required.
The wiring will all be running out the left side so we bent all the anodes in a
counter-clockwise direction. Solder each anode lead together using a soldering
iron with a clean nicely tinned tip. Be quick with the soldering iron and add a
bit of solder to the tip before touching the anode leads. If you're not too
experienced soldering then we would recommend practicing on about 25 test
joints of solid core 24 AWG wire before starting on the LEDs.
You can also get an aluminum heat-sink clip to clip on to the leads between the
joint to be soldered and the LED. We used it on one or two of the more pesky
joints. REMEMBER, too much heat during soldering can kill your LEDs!
It was at this point we first tested our LEDs to ensure we didn't fry any of them with this first
wave of soldering. Using your 12V power supply connect the 3.3k Ohm resistor
between the positive lead on the power supply and the common connected anodes
on the dials and then using the negative wire on the power supply touch each
separate cathode lead to ensure each LED lights.
You should now paint the completed LED assembly
with the black enamel paint to opaque the LEDs. This
is to prevent the stock tach dial LEDs
from shining through the boost gauge LEDs when the
dash is lit. Paint all sides of the LEDs and even the
soldered anodes since it doesn't matter at this point. IMPORTANT: Do not paint
the unconnected cathodes or they will be difficult to solder. Hold the whole
assembly up to a bright light to see if you can see any light coming through
the LEDs from behind. If you see light you need more
paint in some spot. Let the paint dry for about 4 hours.
Now it's time to solder the the
LED wires to the cathodes and one wire to the common anodes. Do this anode wire
first and mark it well with a piece of tape to make things easier for you. We
started by cutting 26 (1 anode wire and 25 cathode wires) 18" lengths of
28 AWG wire and removed 0.125" of insulation from one end of each wire. I
also bent the cathode leads over about 45° beforehand. Starting with the
"20psi" LED we soldered on the cathode wire and continued soldering
the wires on clockwise going down numerically. To make life even easier to
solder, I pre-tinned each of the wire leads beforehand. This will make it even
easier to attach the wires. We then tested each LED again with my power supply
to ensure we didn't fry any of the LEDs.
Since the # of wires gets quite bulky, I decided to split the wires and route
some around one side, and some around the other. Bundle
all of the wires up into a neat package and tie down every .5" to
.75" with the fishing line. I used a upholstery
needle to make running the line easier. Run the fishing line under the soldered
loops of the anodes and over the wire bunch finishing with a surgeons knot (that's
a regular knot but crossing over the ends twice instead of once and then
finishing with just a single knot crossing once):
You can now go over the whole assembly with the
black paint to ensure no light can come through the LEDs
at this point. Let the paint dry.
Step 8 -
Attaching the LEDs to the Control Unit
NOTE: You may skip this step if
your LED wires are already soldered to your control unit.
These pictures
show a complete Boost Control Board with the "Dimmer" technology
marked for wiring order. Note that the common anode wire should be connected to
either of the pads marked +VL on the main
control board.
Once I had everything connected, I decided to test the unit. I hooked the
control unit to a 12v bench power supply, and supplied air pressure to the
sensor with a small compressor. Using the compressors regulator, I slowly
ramped the pressure up and down, verifying that the leds
turned on and off in the correct order. It was at this point I noticed an
error, and was able to fix it. It does pay to double and triple check.
Here are some pics of the dial
during testing:
Your cluster needs to be out of the car and the front
portion of it needs to be removed at this point. If it isn't, do it!
It's now time to replace the tach
dial assembly. You will not be able to twist it on, reversing the procedure you
followed when removing it, because the LEDs and wires
are now in the way. Just place the tach dial on top
and gently press it onto the white plastic centre post until the dial snaps on
over the white tabs. Trust me, they will snap over. The wires are going to need
to make a sharp left turn under the LCD display and then make a sharp right
turn out of the cluster housing... which you will also need to cut a hole for.
We just used the Xacto knife to whittle my way
through the plastic and that only took me about 4 minutes so it's up to you how
you do it. You could drill it out or file it but the most important thing is
try not to get any dust into the front of the housing because it might be
difficult to get out of some of the cracks and crevices in there. That's why we
chose the whittling method since it keeps the waste bits larger and easier to
see and remove:
Step
9a - Testing the Completed Unit
It is best to test the whole setup before you put the cluster back in the
car just to make sure you have everything all in order. It is far easier to
troubleshoot a problem when the cluster is still on the workbench as opposed to
being in the vehicle.
Perform the following:
Step
10 - Installing the Completed Gauge Cluster into the Dash
Okay, time to head back out to the car to install the
modified cluster.
IMPORTANT: Please disconnect the
positive and ground cable on your battery before proceeding. You may want to
make note of any radio pre-set stations since these may be erased when the
battery is disconnected.
Begin by mounting the cluster with both torx
screws. Leave the control box and wires
free in front of the cluster. This will allow you to adjust the unit later more
easily.
Once the wires are in the engine bay, decide where
you will mount the boost sensor. I chose to tie-wrap the sensor to some
existing lines that run near the EGR location.
All that’s left now is connecting the ground. I
chose to connect it to one of the dash mounting points. You’ll see a torx screw in the lower portion of the fuse area. Remove
this screw.
To calibrate the unit, put you key in the ignition
and turn the key to the "On" position without starting the car. Turn
the headlight switch to the full headlight setting. With a very small flat
blade screwdriver turn the "calibration" screw on the control unit
clockwise until a few of the LEDs light up... the
more the better. Then turn the "dimmer" screw either direction to set
the brightness to an appropriate level for night time viewing. Turn the head
light switch off. Now turn the "calibration" screw counter clockwise
just until no LEDs light, then turn it an additional
45° (or 1/8th of a turn): Your unit is now calibrated.
Once it's all back together give yourself a pat on
the back and go for a nice long drive to admire your handy work... but watch
the road too!
Calibrating
the Control Board
Calibration is really simple. Simple
adjustments can be done before you even wire up the LEDs.
It is best to check some basic voltages. All voltages are respect to the
control board’s ground.
Here is what we did:
· There should be about 1.57v on Pin 5 of the Input/Output
(I/O) Bank on pins on the PCB. Or between the car’s stock pressure sensor
output pin (Pin 101 on the ECU) and ground, assuming it is connected to the
Boost Control Unit PCB.
· There should be about 1.4v on Pin 4 of IC1. This can be
adjusted using the Zero Adjustment P1. Turn P1 Anti-Clockwise to increase the
voltage and Clockwise to decrease it.
IMPORTANT NOTE: If the voltage on Pin 4 of IC1 is above 2.0v, very erratic
and inaccurate readings will result. It is best to set this first to about
1.7v.
When you first power the unit on with the LEDS
connected, some of them may be on. Simply turn the 25 turn adjustment trim pot
P1 Ant-Clockwise until the first LED is the only LED that is on. Remember
Anti-Clockwise Turns the lights off and Clockwise turns them on. If you are in
doubt, simply turn P1 Clockwise for a few turns until the lights come on. Then
turn the adjustment trim pot Anti-Clockwise until LED 1 just goes out + about
1/8” of a turn. That’s it, you’re done!
This adjustment is also really simple. You may
need to wait until dark to do this. Simply apply +12v to pin 2 of the I/O bank
of pins, or just turn on your lights if you have wired it up to the car’s light
switch. When in operation the lamps will be noticeably dimmer. You may want to
adjust Zero Calibration (P1), with the ignition on but with the engine off,
Clockwise to turn some lights on, (only a few of the lower LEDS will be able to
be turned on) so a few indicators are on. You can then adjust the dimmer’s
night setting adjustment (P2) Clockwise to set them dimmer or Anti-Clockwise to
set them brighter, until you get the desired brightness. Once this is complete
you may have to re-do the Zero Calibration of P1 as mentioned earlier.
We hope you find this article interesting. If you would like more information, please email us or go to our Gauges For Sale pages.