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.