Major System Category: ISIS Wiring Task: Wire up the DRLs Parts: Power Cell: 1 Circuit: 8 - GREEN Master cell: BLUE/LIGHT BLUE Prerequisite Tasks: Mount DRLs Additional Costs: Time Requirement: 90 minutes Date Started: August 10, 2013 Date Completed: August 10, 2013
A good chunk of the front end wiring never got completed in April 2013. When I returned from the Southern Man Cave, I spent the first seven weeks working on the body. In northern climes, you really need to take advantage of the warm weather months! The GTM has been living with dangling wires from the DRLs, power cells and other things. I left them to hang down behind the grille, and it looked like a real mess.
This is an early photo of the passenger side DRL mount. You can see wires dangling over the side. This is not the first GTM to have DRLs.
Fortunately, I have wiring diagrams worked out for these circuits. In addition, I have a spreadsheet in my master build document that goes into detail about each circuit. I will be sending this spread sheet along with my next order to ISIS Power for the remaining power cells, motion cell and master cell coder. This is because I need ISIS to prep a file that can be downloaded into the master cell for my specific circuit set up. With five power cells, I am pushing 50 circuits - there's a lot going on in the car.
This Gen I GTM in Poland mounted the DRLs above the front grille. I am finding that this area is very busy. I use the upper lip of the front grill to manage the cross connection between head lights, hazards, fog lights. I'm not sure I would want to add the DRLs there. I corresponded with this builder, and asked him about the DRLs. As in every case, GTM builders are quite happy to share their knowledge.
This is half a terminal block. Easily cut with a hack saw.
The DRLs were cut into the body to the left and right lower corners of the grille opening. The fiber glass is very thick in this area, and it is tough going. The wires coming off the DRLs is 22 gauge (not the easiest stuff to work with). Initially, I thought I would create some kind of socket to plug these into, but since I plan to add Angel Eyes around the head lights into the DRL circuit, the idea of some kind og 6 way splice become unmanageable.
I daisy chain the terminal block to create a single circuit. Then I just need a single to power or ground.
Over May and June, I worked on the Intellitronix Dash for the cockkpit. One of the techniques I used here were terminal blocks. Now six way splices are easy. The white plastic terminal blocks are very easy to customize. They come in strips of twelve connections and the strip can be cut apart with a hack saw. I need six connectors for the ground and six connectors for the power leads. That is: 2 x DRLs, 4 x Angel Eyes.
These are the power and ground terminal blocks for the DRLs. The green wire is from Power Cell #1, Circuit 8. The black ground lead hasn't been connected in this photo. The terminals were bonded to the hood using 3M 8115 panel bond.
Note: Angel Eyes cannot be installed after final paint is complete. This is probably 12 to 14 months in the future (and it could slip to Spring 2015). However, the Angel Eyes need a place to connect, so I AM building that now.
The hood mounting is problematic due to the variables associated with centering vis-a-vis the rest of the car.. I explain to people that there are 100 ways to mount the hood, and I settled on the 101st position. I have made the decision that hood will remain attached to the car and it will need to be painted in place. Everything else can be removed. To this point, a great number of things have been permanently mounted (e.g. lights, signals, parking sensors) and the wiring associated with these peripherals.
I mounted the terminal blocks above the front grille opening on the interior of the hood. This is convenient, because most of the wires can run directly to these terminal blocks. The ground is to the chassis area that supports the AC condenser, radiator and fan assembly. The power lead runs to Power cell #1 and is enclosed in wire loom. I made sure I left enough slack in the wires so the hood can open and close without pulling something loose.
<< Intellitronix Create-A-DashHorn - Circuit 1/9 >> Major System Category: Electronics Task: Wire terminal blocks Parts: Terminal Blocks Prerequisite Tasks: N/A Additional Costs: $12 Time Requirement: 3 hours Date Started: May 19, 2013 Date Completed: May 19, 2013
There are close to 30 wires coming out of the back of the instrument cluster. I had focused exclusively on getting the cluster built that I did not consider what came next. Obviously there is some order to all these wires, I just need to read the instructions that come with the kit to figure where everything goes.
Lots of wires in a bunch of different colors, but they all mean something. Once you understand the meanings, then the pattern becomes clear and the solution is obvious.
Fortunately for me, this is not Intellitronix first shot at wiring instrument clusters together. There are basically five groups of wires:
Ground (black)
Power (red)
Dimmer circuit (purple)
Indicators (various colors)
Sending units (various colors)
The solution is something called daisy chaining (at least that's what it was called 30 years ago). I purchased this terminal block from Radio Shack. I then wired each terminal to the next terminal. This means that a single lead can be run to a grounding point for all wires running in the bottom side of this terminal block. Since these are grounds, i wasn't worried about something arcing over.
There are 9 ground wires, 9 power wires (these can segregated into two groups) and 6 dimmer wires. The ground wires are obvious. They need to be ground to the chassis, but ganging 9 ground wires to a single grounding point is unmanageable. Similarly there are 9 power wires. The six attached to the gauge cluster need to be run to the ignition. There is not enough room on the ignition terminal to run another 6 wires. Finally, the dimmer wires need to be spliced into the head light switch (oops).
This is an insulated terminal block. I used this type of block for everything except the grounds. I daisy chained this block and the one for the dimmer circuit. That way I only had to run 1 lead to each source. This is a much more manageable arrangement.
I purchased three terminal blocks from Radio Shack. For the grounds I could go with an open terminal block. For anything related to positive current, I opted for an insulated terminal block. I discovered I could cut apart the insulated terminal blocks. So I fabricated 2 six wire, 1 five wire and 1 three wire blocks.
From left to right, the dimmer, ground and power terminal blocks. The leads coming in from the top come from each gauge. Plus the ground terminal block also received leads from the signal and high beam indicators. Before I mounted these for real, I clamped everything to my test battery. As long as the gauges lit up, it means my terminal blocks are working properly.
The Factory Five carbon fiber back board curves in. this provides a shelf where the terminal blocks can be mounted. I mounted the terminal blocks using 3M double side tape. I had wire for the power and ground leads, but nothing for the dimmer block. I know I have some wire at the Northern Man Cave, so I'll take care of that when I get back.
The top three wires are leads from the GTM kit supplied indicator lights. The bottom wires are leads from the speedo gauge. Since I have a terminal block, it should be fairly easy to run these leads into the steering column circuit. I probably am going to need another terminal block to handle signals coming from the front and rear of the car.
The speedo gauge has two white wires and a brown wire. The instructions says that the white wires are labeled on the gauge printed circuit board as left and right. In agate-agate you can barely make out something that looks like right. The left and right white wires are connected to the respective turn signals. The brown wire is connected to the high beam indicator. Somewhere along the line these have to be wired into the switch on the steering column.
Sending unit terminal block.
The final terminal block is for sending units. These connect as follows:
Green - Connects to the ignition coil or the direct tach output lead.
Blue - Connects to the water temperature sending unit.
Gray - Connects to the mechanical speedometer cable.
Yellow - Connects to the fuel sending unit.
Orange - Connects to the oil pressure sending unit.
Terminal block set up on the back side of the instrumentation cluster. This certainly makes a lot more sense.
Prerequisite Tasks: N/A Additional Costs: $434 Time Requirement: 8 hours Date Started: May 10, 2013 Date Completed: May 18, 2013
The instrument cluster has been something that has bugged me about the car from the beginning. I wrote a post in January 2012, discussing this issue. Basically, the GTM is a WOW car. The lines, the performance, the handling all combine to create something special. Then you get in the car, look at the gauges and go, "Huh?" One of the major complaints about the C5 and C6 Corvette generations is that the interior does not match the exterior. One of the knocks on the GTM is that some people don't bother to finish the car. GTM 402 will be finished, and part of that, includes the WOW factor.
This is a task best done on a bench. This multi angle Stanley vice is fantastic for this job. I have one at both the Southern and Northern Man Caves. In this photo it is holding the Factory Five carbon fiber backboard used to mount gauges. I taped it to protect the surface. I have also used this vice to help crimp connectors, and I can mount almost anywhere on the car or the lift.
In the January 2012 post, I looked at Intellitronix, Speed Hut and Dakota Digital. I also considered the all in one dash consoles with data recorders, but these were running over a $1000 and I just didn't like the look. This entire task is about the look. Around January 2013, I decided to take another look at the the instrumentation puzzle. I came across Intellitronix's Create-A-Dash kit. At first I rejected the idea, then I came to realize this was exactly what I was looking for. Then I saw it on Stacey David's Gearz program (for a car builder this is a good show for ideas).
I planned to work on the instrumentation gauges on my current hiatus at the Southern Man Cave. I drop shipped the Create-A-Dash kit via Amazon and packed the tools I needed for the task. The gauges are available in white, green, blue or red. I watched a fair number of videos. I didn't want white (it just seems blah to me). I thought I was going to order blue, but it turns out red worked for my eye sight better.
The kit includes everything pictured here: Speedo, tach, volts, water, oil and fuel, smoked Plexiglas cover, backboard mounting hardware and sending units.
Each gauge requires eight spacers. You place the short ones against the base board and the longer ones between the gauge and the Plexiglas cover. There are a bunch of little bolts, nuts and plastic spacers for mounting. I poured them into a magnetic parts bowl. It is very easy to lose one of these small parts. Intellitronix recognizes that most of us drop things into to distant corners and includes extras!
To protect the backboard I cover it in blue painter's tape. The locations of each gauge is marked on the tape.
I super glued the spacers to the printed circuit boards. I know from experience that I don't do well with little parts, and anything I can do to make them easier to handle is worth the extra time.
I used the packing Styrofoam panels to support the gauges as I glued the spacers to the printed circuit boards.
My first idea was to drill a hole behind each gauge, install a grommet and run the wires to the rear of the panel. This doesn't work. The wires are too stiff to be bent so they can fit through a hole hidden by the gauge. I ended up drilling a hole for individual wires and cutting a slot for groups of wires.Once the smoked cover is mounted, these details are obscured.
The back side of the fuel gauge. The four wires coming off the end can not easily be bent to go through a hole, so I just let them go straight to the back board, where there is more room and slack on the other side.
I did a fair number of measurements to make sure I had things lining up properly. The bigger gauges measure 3.25 x 3.25 inches. They are smaller than the round five inch gauges and they use space more efficiently. The smaller gauges are 1.625 x 1.625 inches versus a two inch round gauge. This allows me to easily deploy six gauges on the back board with space to spare.
Gauge set set in place on the back board. You can see the lines I drew to help me get things set up. I worked off a center line. The center line is approximate, because the Factory Five back board is already cut and it seemed like the curve is slightly different from side to side.
There is some wiggle room for mistakes, but I tried to keep those to a minimum. Prior to drilling and holes and cranking bolts, you can get a good idea how things line up. The wires are stiff enough to support the gauges. I used a 5/64 bit to drill through the holes on the printed circuit board and into the back board. then I widen the holes on the back board with a 7/64 bit. I rifled through my Allen wrenches until I found one that fit into the head of the supplied bolts. The 1/4 inch nuts on the back side are easily handled with a ratchet.
Gauge set bolted in place.
The multi angle vice really came in handy. I could turn, spin and position the back board all different ways. There is no specific torque spec here, so just use common sense.
I couldn't resist. I hooked everything up to my 12v test battery. Note: If you get confused on the little gauges, just hook it up to a 12v source and they will tell you what they are.
The next part involves cutting the smoked Plexiglas cover. The kit provides a generous piece. You could almost get 2 covers out of a single piece. I positioned the Plexiglas sheet behind the factory Five back board, and held it in place with duct tape. I traced the curve. I discovered things here are not perfect either. I used a jig saw to cut the piece, then steel wool to smooth out the edge.
Cut Plexiglas piece.
I decided to use three bolts to attach the cover to the back board. I made a quick trip to Home Depot and picked up bolts, nuts and spacers. I trimmed the spacer to 5/8 inch. This way did not put any pressure on the gauges or the bolts holding them in place. I installed the connecting bolts on each side and on the center line between the speedo and tach gauges.
Hardware to connect the screen cover to the back board.
There remains the problem of the little toggle switches on the tach and speedo gauges. I hit on the idea of looking at the switches sideways. I used a straight edge to run two lines and plot the intersection point. Then I drilled a large enough (5/16 inch) so the switches could go up, down, left, right.
The circle is where the toggle switches come in contact with the cover. I was able to eyeball the location of the toggles with the aide of a straight edge. Once I had an intersecting point, I just had to drill a hole.
The final step is to install the high beam and signal indicators from the Factory Five kit. I decided these needed to be mounted on the surface of the cover, because they are not as bright as the Intellitronix gauges. I wrapped the wires in electrical tape (I should have brought some black from the Northern man cave) and ran the wires from the cover through the back board. I super glued the indicators for extra security.
The wires are wrapped in green electrical tape. The signal indicator is surface mounted on the cover.
Next steps involve adding a wire block to the back of the back board to handle all the wires and fabricating a gasket to run along the edge of the between the cover and the back board.
Not the greatest photo, but you can see the high beam and right signal indicators.
Here's my dilemma: I am in the process of building this incredible car. The GTM has an exotic body shape, a power/weight ratio that is otherworldly and a performance envelope that competes nicely with top end Ferraris and Porsches. I must admit - this is not an easy topic, because I haven't found anything that fits my idealized image.
My basic requirements for the gauge set are as follows:
Speedometer (200 mph minimum)
Tachometer (with red line indication)
Voltmeter
Oil Pressure
Water Temperature
Fuel
The stock gauges supplied with the kit are made by Autometer. These are fine guages that have a utilitarian look, not a supercar look. SO I embarked oin a search for something that reflects the GTM's supercar nature.
Stock gauge cluster supplied with the basic kit.
The first thing I discovered is most speedometers cap out at 120 or 160 mph. The GTM tops out somewhere north of 200 mph. This eliminates approximately 80% of the gauge sets currently available.
TPMS panel. I plan to mount this flush on the lower left side of the steering wheel.
The next problem is available space on the instrument panel. In addition to the guages, there needs to be room for turn signals, high beam and the radar detector screen. At the lower left of the instrument panel, I plan to install the TPMS (Tire Pressure Monitoring System) display. With the exception of signals, cruise control, stereo system and the Escort 9500ci controls, all other controls will located on the inTouchMax controller on the center console north of the gear shift.
Escort 9500ci display. This will be on the central dash panel.
Intellitronix makes a very nice digital gauge set. They will work with you on customization and they satisfy the basic requirements. They provide an analog/digital combination.
Intellitronix gauge set.
Dakota Digital has a number offerings. Their new product is an Oval Speedometer/Tachometer Information Center. This has everything except the water temperature. However, it incorporates turn signals, idiot lights, odometer, analog tachometer and software to record 1/4 miles and 0-60 performance. They offer a universal instrument cluster (it is as ugly as sin).
Speed Hut has a number of gauge sets. They have an online customization program that is quite flexible. In addition, they will further customize anything you want. One of the attractive things is their quad gauge. Instead of 4 holes drilled into to the dash panel, it combines the volts/oil/water/fuel into a single gauge.
Quad Gauge combines four gauges into a single unit.
Do I know what I'm going to put in the car? Not yet. Several times I have thought I had reached a decision, only to pause and search some more. I don't have to make a decision until later this year.
