Cockpit wiring, Lighting & Electrical Test

Ignition & Column Wiring

I paid GBS to modifying my Column stalks to work with their own loom. This simply plugged in. The only job for me here was to prepare the ignition wiring and adapt it to the GBS connector. Simple enough I hoped.

I located the ignition wiring connector on my old Mazda loom and looked up the functions of each wire. Mine is a Mk2.5 which is slightly different to the Mk2. Looking at the GBS loom schedule I worked out connections.

Mazda 2x White / Red  -> GBS red --- 12v fuse supply

Mazda White -> GBS pink --- Starter solenoid

Mazda Black / White -> GBS Yellow --- auxiliary isolator relay switch

Mazda Blue -> GBS all blacks --- 12v ignition out

Mazda Black / Red -> not used

At first I seemed to have power when the ignition was off. Mysterious. Checked all sources that confirmed my wiring was good. By process of elimination I started with the Mazda Ignition barrel itself which turned out to be the issue. Took it apart, cleaned it up and hey presto I had power!

GBS loom side

Mazda Connector Side

I intend to added a start button but will leave that for another time.

Lower Dash Loom

I thought I would save some hassle by buying the lower dash loom from GBS. At best its a half a job as the wiring for the hazard warning lights is not done, so should not have bothered.

I am going to have switches for hazard, horn, washer and rear fog lights. I found these double pole illuminated aluminium savage switches on carbuilder.com which looked nice.

I will also add a USB socket, haven't made up my mind about a 12v socket.

On the positive side I found a wiring diagram for all my switches on technical downloads section of the GBS website.

I scavenged the additional wiring from old Mazda loom I have kept and bought some better sized spade connectors than were provided with the lower dash loom. I got some Zener diodes and soldered them in. Got the diodes the wrong way around to begin with but a quick switch and all was working as intended. 

Lighting

I bought the lighting kit from GBS which included halogen headlights, LED front indicators, rear fog, reverse & rear light clusters which include brakes and indicators. Should be plug and play.

Testing

With most of the wiring complete I've kept a list 

Dashboard Gauges & Sensors

Really nervous about this part, ripe for screwing up. I had a bit of tile backer board that I used to make a template for the dashboard to match the scuttle. I then protected the dash with masking tape and set about cutting. Used a dremel type tool with a cutting disk that gave a reasonable finish, then did the rest with sand paper. Wore a mask of course!

I made a cut out for the steering column and checked the final fit.... alright, took to much off. It's only a small gap each side so may be able to make good. May use some edge trim anyway. Decided to carry on and can always improve later as only aesthetic.

Next stage was the instruments. I went for the ETB Gauges with the black bezel and asked for red needles. Really pleased with them. I got a steel instrument surround i used as a template for the layout but may end up not using it. I drilled some centre holes and then used a holesaw on slow a bit smaller than the target diameter for each gauge. Then I finished the right size with sanding. Got a good finish without cracks. So far so good!

Once the holes were good, I added the instruments. With the GBS loom it is all straightforward once you know which colours wire are which. The speedo and Tacho have unique connectors. For the 52mm instruments, spade connectors are used. Each signal wire has a unique colour so is easily identified.

Oil = Orange Water = Blue Fuel = Yellow Oil = Voltage = Brown

The green wires are for the illumination of the dials off a switched power source. Brown wires go to Earth, Black to 12V.

A quick test power on......

I will use bond in studs and wing nuts to connect the dash to the dash support panel, but for now have left it loose. I also may wrap the dash to make it a bit more interesting, but aesthetics are for another time.

With the instruments came the fuel sender, oil pressure sender, speed sensor and temperature sensor. Installation was quite straightforward.

I bought a T piece from eBay for the oil sensor so it could share the same port on the engine as the ECU oil sensor. 

A small aluminium housing was used in the heater delete coolant hose to house the temp sensor. 

The fuel sender just slides into place in the tank, but an additional earth was added here for the fuel tank, and the loom sender wiring needed modifying and extending.

PICTURES HERE!!

Bonnet & Nose Cone

The manual advises that the bonnet and scuttle is a two person job. Unfortunately there's only me so that will have to do.

The nose cone fixings were very simple. Stainless m6 rivnuts in the handy upper holes. Then under the radiator there are some pre drilled holes. I used some m6 chimney nuts and positioned them accordingly. 

Offering up the nose cone, I clamped it at the bottom with some adjustable clamps. I centred it laterally first and then set it longitudinally so that it was very close but not touching the upright mounts where the top rivnuts were located. I then realised I had to remove the radiator assembly to get to the lower rivnuts..... grrr.

Nose cone in rough position

After following the same process again I then offered up the pre rolled bonnet. It was a country mile off the right shape! So before I was confident to fix the nose cone position I set about the bonnet.

Bonnet a mile off!

First off was to fix the bonnet pins. I chose black. I wrapped them in tape to give some (but not enough) protections. I installed some M6 rivnuts into the side chassis rails. Then i needed to enlarge the bonnet pin holes in the bonnet to allow the bonnet a chance to match the side panels. I also temporarily installed the bonnet catches (pre drilled holes that were actually in the right place!) and protected the nose cone and scuttle with tape.

Next job was to bend the bonnet. I removed the VVT housing and pipe from the top of the engine and cut a small hole in the bonnet to deal with what's left that will clash. Eventually there will be a scoop so not worried about the hole. With some heavy liquid filled plastic containers and a large roll of plastic carpet protector (the only solid cylindrical object of large enough radius in the house) I set about some large adjustments to the bonnet.

I first flattened it as much as possible and then rolled the bonnet around the cylinder to try and get the shape. The bonnet must have gone on / off 50 times and I flattened / deformed so many times but eventually I got it about right. I temporarily installed the edge trim and I think the result is acceptable. Need some more bonnet pins as they are so scratched up they are no longer black!

The final bonnet shape

A few minor dents (will be cut out by the scoop) and minor scratches (will be prepped out for paint) and I was happy enough with the result. So I drilled pilot holes in the nose cone through the chassis fixings and firmed things up.

Next step are cut outs for the exhaust manifold and scoop!

The exhaust cut out worried me the most as there is no room for error. Measure a million times and cut once.... Time for a bit of CAD (cardboard aided design). I installed the exhaust manifold and measured the approx centre of each of the pipes as they passed across the outer chassis rail. I drew the centres on a piece of cardboard (coco pops I packet I think) and used a french curve to make a nice shape to aim for a 10mm clearance to the manifold. A quick cut out later and I had a template.

Template in place

I transferred the pattern onto the bonnet and then set about it with a Dremel 38mm cutting disk for a rough cut out, and then a file to finish. I cut inside of the curve to ensure I didn't stray outside the line. This left me with a lot to file off but better that way. I reinstalled the manifold, measured and finished the job. A bit of trim around the cut out and it will look good.

View from the front

View from the rear

Next step was the scoop. The VVT housing and oil pipe on the engine clash with the bonnet. I considered a few different options. A formed bulge, lowered engine mounts were thoughts, but I decided on the scoop. I like the look and it offers flexibility in case I want to do something else under the bonnet later.

The scoop itself is a GRP one from GBS. At £90 it felt good value against other options. Since the bonnet will be painted i thought going for a carbon one a waste of money.

I centered the scoop on the bonnet and straight away realised the shape of it is not a great match to the bonnet curve. Only bonding it would be difficult to achieve so I decided to use a few countersunk rivets when installing it. That made it even more important that the cut out was well sized but not too over sized as I will want the filler to cover the rivets.

Big hole!

I used a cutting disk on the Dremel again to to the hole. I went through two discs but it was generally easy to keep steady. I finished the cut out with a file.

Nice and central

Scoop and exhaust - looks like a car!

A bit of filler and sanding will be required to finish the edges of the scoop cleanly but quite happy with how it is looking.

Engine & Battery Loom

 I decided that I was going to run an Emerald K6+ ECU and throttle bodies, so it made sense (at least for ease) to use the GBS wiring loom. I was hoping the £600+ price tag meant it would be super easy..... To be fair it does make it much easier, but there is still a fair bit to do.

I received the loom and battery lead kit from KitSpares. The loom is well marked and looks good quality. The battery lead kit came missing the terminal covers, and as soon as I picked up one of the cables the crimp came off one end. Quick call to GBS and it was sorted very quickly indeed.

First job was battery lead from battery to starter. I decided to run this low past the RHS engine mount in some split conduit p clipped and cable tie mounted at IVA compliant intervals. I would use that same conduit to run the cable to the crankshaft sensor on the bottom front left of the engine. Since GBS provide a plug to take both the cam and crank sensor wiring, I had to make up this bit of the loom. I sourced some wire from my existing Mazda loom, bought a new camshaft plug & pins (BOFI racing) and also managed to source the crankshaft loom side connector from eBay albeit from China. Some crimping and swearing later, I had a mini loom! My wire colours have changed from standard, so here is a record of them....... 

Cam & Crank Sensor

Sensor    GBS Pin    GBS Wire Colour    Mazda Wire Colour    Rob's Wire Colour

Crank 12v      1           Black                  White / Red            Orange

Crank Sig       2           White                 Purple                   Purple / Red Stripe

Crank Grd      3            Blue                  Black / Blue           Yellow / Green Stripe

Cam 12v        1            Black                White / Red            Yellow / Red Stripe

Cam Sig         4           White                 Grey / Blue            Purple / Blue Stripe

Cam Grd        5            Blue                   Black / Blue           Yellow / Black Stripe

The battery cable and crankshaft loom run in the split conduit past the engine mount

The battery lead p clips to the battery earth point. Battery earth cable is attached ready for the battery

Crank shaft sensor wiring comes out of the split conduit. Needs securing with some cable ties.

Should not forget the engine earth on the exhaust side of the engine

Engine Earth

Next was the VVT sensor. Loom tail far to short so I bought a new connector and made up a new loom myself.

Next the the coil pack loom needed to be sorted.

Function    GBS Wire Colour    Mazda Wire Colour

Cyl 1&4     White                    Brown / White

Cyl 2&3     Yellow                   Black / Yellow

Ground      Brown                   Black

12v            Black                    Black / White

Coil Pack Loom

Now for the main loom, the first job was to position the ECU as a monument for the loom. I copied an idea from a well known blog and use a piece of aluminium to extend the fuse box mounting plate to place the ECU beside it. The loom from the ECU plug was then routed to the left into the tunnel.

Emerald ECU attached to aluminium plate

Loom routed to the left of the ECU to leave access to the brake pipe union. The tied to the brake pipe before entering the tunnel

By my reckoning, the loom had too much of a tail on it and so would need to be routed to effectively shorten it. Therefore, I took the loom cable to the left of the fusebox and into the area above the gearbox to give myself room to lose some length. I then figured the best place for all the engine loom connectors was on the RHS (intake) side of the engine and try to hide them underneath throttle bodies. 

I also ran the fuse box to starter motor battery cable into the tunnel at the same location.

Engine loom and battery link into tunnel to the left

Losing some length in the space above the gear box. Whilst it's not that pretty, it is very secure and out of sight. To relieve congestion, I ran the battery cable out of the tunnel on the LHS and take it across the engine bay slightly ahead of the chassis cross member.

Losing length on the engine loom

Using a piece of aluminium L section attached to the two circular chassis members through P-Clips I run the battery cable across the engine bay and will also run the cable for the lambda sensor to be secure and out of sight.

Aluminium L Section To hide some more cables

The engine loom exits the tunnel on the rear RHS of the engine. Because of the loom design all the connectors are close together, but I didn't wanted something a bit neater than just tieing them to the tubular chassis member. So I made an aluminium bracket to secure a bridge across the chassis for all the engine connectors bar the lambda connector. I rivetted some Deutsch connector clips to the bracket so they are securely held and can't drop onto the steering column whilst also not able to chafe with fuel pipes or other bits. They can also be released quite quickly in case removal is needed. The cables are mostly hidden underneath the air filter so whilst not invisible are not unsightly. May tidy a bit more in future.

Engine Connector bracket

Throttle Bodies!

I was not convinced I would splash out on the GBS ATR throttle bodies, but I am glad I have. They came nicely packaged in the post and fully assembled with the TPS sensor ready for wiring.

First job was to clean out the intakes on the engine block. A little wire brush and some elbow grease sorted that. Not in a bad state for a 20 year old engine with 80000 miles. I also removed the studs from the block so I could use the nice bolts provided in the kit. Using the two nut method to get them out worked OK with only one scraped knuckle.

Cleaned intake ports!

I then installed the little blanking plugs where the old injectors would be which were provided (at a price!) by GBS. Nice tight fit. After a bit of mucking around I realised the TBs needed to be disassembled to fit onto the block. First was the black part that mounted directly to the block with a fresh manifold gasket. Go easy on the torque for these bolts as the head material is quite soft. I used 22Nm torque.

Part1 of the bodies installed

The next part could then be attached which was straight forward. The trumpets then screw on but the filter plate is meant to go on first.

Trumpets!

The black fuel rail was then put on with the long bolts. I used a bit of vaseline to lubricate the o rings on the green bosch fuel injectors to ensure not to tear the o rings. Looking good so far!

Fuel Rail

The filter back plate is held on by the trumpets and will house the air temperature sensor with an M12 nut with a funny thread. The pipercross filter fits on the back plate with some 25mm DZUS fasteners to make it quick release. Before installing all of this it makes sense to organise and tie up all the engine loom connectors and sensors (like the oil pressure sensor) because space is very limited.

Filter Installed - I think I prefer the Bare Trumpets....

Front Fuel System

The front fuel system is relatively easy to sort but it in quite a tight space. It consists of a high pressure pump, swirl pot, fuel pressure regulator, lot's of pipe and in my case some lovely ATR throttle bodies!

First thing I did was to mount the high pressure fuel pump and the swirl pot. The high pressure fuel pump is mounted to the drivers side footwell panel using some rivnuts, large cable tie clamps and some heavy duty metal cable ties.

The swirl pot comes with a bracket and is mounted directly to the chassis using rivnuts as close to the footwell panel as possible. This is best done with the side panels off for access!

Swirl pot and fuel pump side view

Fuel pump and swirl pot top view

The large 13mm ID diameter high pressure pipe provided by GBS goes from the swirl pot to the bottom of the fuel pump. This required quite a bend in the fuel pipe. I used an internal pipe bender to avoid it kinking and got the shape I wanted. It was then p clipped to the chassis to avoid chafing. The red (feed) nylon pipe then attaches to the top of the swirl pot using some 8mm id fuel pipe of the correct spec. This runs quite close to the steering shaft so it makes sense to have that installed to ensure clashes are avoided.

I then waited for the throttle bodies before completing the system. I made a little bracket to attach the ATR fuel pressure regulator to a spare hole on the rear right of the engine which gave a very short run of pipe to the throttle bodies. It doesn't matter which end of the fuel pipe you have the regulator so I thought this was quite a neat solution. The bottom of the fuel regulator then attaches to the of the two outlets on the side of the swirl pot. I routed a pipe vertically downward and fashioned a couple of little brackets with cable tie clamps to secure the pipes without the possibility of chafing.

Another pipe run goes from the far end of the fuel rail and loops back to the top of the high pressure fuel pump. The pipe is secured to the tubular chassis rail using a home made bracket, and then along the top side chassis rail using p clips at IVA compliant intervals. Very secure!

Fuel rail to high pressure fuel pump

The final run of pipe is the return to the fuel tank which attaches to the black nylon fuel pipe and the bottom of the two outlets on the side of the swirl pot. Ignore the green tape, just waiting for some pipe separators to neaten it all up.

Final piping for the swirl pot

I would highly recommend having the engine loom in place, or at least an idea of where it is going to go to do the fuel pipe runs. The whole area is very congested and clashes can be easy. I also recommend purchasing a few 23mm p clips to use on the circular chassis rail. It avoids drilling unnecessary holes and in general all of this will be hidden once the throttle bodies are properly installed.

Driveshafts

For the Mazda, new driveshafts are required because one is longer than standard and the other is shorter. GBS found a new supplier who manufactures new shafts instead of the friction stir welding process performed on the existing ones. Pricey!

The existing CV joints need to be removed from the old shafts and then installed on the new ones. This is fairly straightforward but messy process. Lot's of blue roll required.

The process for the inner CV joint is as follows

Remove the driveshaft retaining clip and retain (or replace). Remove the boot. Carefully remove the large C-clip in the recess of the cup. Slides the cup off the shaft and make sure to catch the 6 ball bearings. Remove the small C-clip in the recess on the shaft. Rotate the cage and remove. Gently tap the 'petal' off the shaft using a rubber mallet. Remember the orientation of all the components for reassembly!

For the outer CV joint it's a bit different. 

Using a soft drift (piece of wood) held against the 'petal' closest to the shaft, tap the entire assembly from the shaft. If you want to clean up for fresh CV grease you can disassemble the assembly. Use the driveshaft to rotate the assembly as far as possible so that one of the ball bearings is nearly exposed. Take out the driveshaft continue to rotate the assembly so one entire ball bearing is exposed. Using a pry, remove the ball bearing. Repeat for the rest of the ball bearings. Then the cup and petal can be separated. Be careful, the direction of the cup and petal is important.

I wiped down all the components and removed the remaining grease from the cups with the intention of completely renewing it. I carefully inspected each part and found that for 20 year old parts they were in really good condition.

CVs disassembled & cleaned ready for re assembly

Orientation of outer CV joint cup - curved bit of hole toward shaft - warning! Petal is not symmetric and orientation is important!

Orientation of cup on inner CV joint - petal is symmetric

Last thing to do before reassembly is to clean of the decades of surface rust, apply some KuRust & then paint. I choose some 'Extreme Chassis Black' for durability & also painted the exposed parts of the driveshafts.

CV Joints in the painting process

Reassembly of the driveshafts is in the opposite order to the disassembly. I found all the C-clips were in good condition so I retained the originals.