https://www.facebook.com/265560833307948/

A Viking’s Journey into GD MK4 land

Home
United Kingdom
Sevenoaks
A Viking’s Journey into GD MK4 land

Directions

This page is to catalogue my joys and exploits in building a Gardner Douglas MK4

30/10/2026

Embracing the plastic fantastic

So as part of this incredible build journey, I have been privileged to chat with so many builders who have the skills and knowledge around so much of the “modern technology” of CAD and such like.

Whilst I learnt the basics of CAD at university some 40 years ago when I read engineering (and Fortran and COBOL were the languages of choice!) I have not really kept up with that having moved into the heady world of finance. So some of you have been the victim of my enthusiastic mind and total lack of skills.

That needed to change, especially given my plans for lots of bits and pieces for the build (and of course my workshop!). So today the nice Mr Postman brought me a nice new shiny toy to play with since I took advantage of a great BFCM deal at Bambu on their P2S printer -AMS 2 Pro combo.

Lots to play with over the weekend getting it set up and the first “benchy” printed, then it’s off into storage module printing to sort out my tools etc whilst I (re)learn some basic CAD. Anyone with a recommended platform let me know - I hear good things about Fusion 360 but I’ve yet to embark on researching that particular path - it’s taken me months to get comfortable with Bambu believe me!

So here is a picture of a box to keep you all happy

20/10/2026

Tying up a few loose ends…

Don’t we all love a change in the seasons? Those dark nights drawing in makes the mind turn back to indoor works and the garden slowly goes into hibernation.

So I’ve been back playing with Hela and getting these damned electrics finished. The dash is now fully wired and tidied up, labelled and the wiring spreadsheet updated for all my mad cap things.

That left me to sort the dash wiring and all the multiplugs, which has all been encased in suitable conduit and again labelled to within an inch of its life. I have also sorted the jumble of wires, trimmed the return edge of the dash to allow the switches and gauges to sit flush and then had to work out what to do with the heater hoses. Bloody big annoying things.

Now, I don’t like things hanging loose and rattling round behind any panels. Even a small squeak drives me round the twist. Elsewhere I’ve used SikaFlex and some tie wrap bases to secure the wiring to the shell, but the heater hoses proved too much for that particular solution. Cue head scratching. Then I remembered the big head screws I had used elsewhere. I wondered if they did anything that might suit for a tie wrap base - after all, a fibreglassed fitting is never (hopefully) going to give way.

Cue drum roll and yes, they do something suitable so a quick order with East Coast Fibreglass Supplies and ten of these beauties turned up. Certainly not cheap at over £4 each, but what price perfection (I’m sure I could print something suitable when the Bambu arrives but for now I’m still relying on third parties.)

After mixing up a small batch of the old P40 they have been installed and given a good old tug to make sure they won’t let me down. All safe and sound so that’s another little job ticked off the list. And that list is getting shorter and shorter so I might just have to think of some other things to dream up. Like a nice way to mount a removable radiator grille or grilles over all four of the front openings. Or an arm rest with iPhone charger in it. Or…

Thanks for reading

06/10/2026

The end may be in sight…

Well, of the dash electrics anyway. As those following will know, it’s a labour of love and OCD dominance to sort the wiring out especially if you veer away from the standard GD wiring. Since I’ve added lots of toys and things, it taken a while and about a couple of miles of the finest colour coded wiring to overlay the GD stock loom with everything.

Thankfully I’m coming close to the end of this part of the journey. The dash itself is fully wired, just some tidying up of the cable routes to do and a few labels left to add. The front body loom is also nearly done with the label printer working overtime as I have gone back and documented all the various wiring bundles. Because I am fitting a heated front screen and Speedhut gauges, I am fortunate to have plenty of space behind the actual dash for all the wires and other gubbins. I’ve also done all the pre-wiring for feeds to the Canems ECU, the EPB module etc so hopefully most of the bases are covered and I won’t have to unwrap all this anytime soon.

So a couple of the obligatory pictures - one of the loom wiring in the dash and the other of my connection spreadsheet that will be used to build the final wiring book / diagrams.

24/08/2026

‘Ere wago ‘ere wago

Just a quick update on the power and illumination circuit for the Speedhut Custom Gauges. As mentioned elsewhere, Speedhut don’t make a series harness for the LED gauges so I’ve had to come up with a solution of my own.

I’ve used Wago connectors on my model railways and around the house for years and my local sparky uses them all the time, so I’m confident they are good for the job at hand. Part number 2773-408.

Each one takes up to eight wires all connected together just like a compact bus bar. More than capable of handling the load from the Speedhut dimmer controller.

The connectors need a rigid wire input, so I used a good quality ferrule on each wire and they locked nice and firmly into the connector block. Each block will then be bonded onto the back of the dash.

Works a treat and hopefully an idea than might be of some use to others.

23/08/2026

Surviving First Contact?

Well I know it’s not starting an engine for the first time or anything as exciting as that, but having had a little bit of build fatigue over the last month or so, I was very lucky that SWMBO gave me a couple of days this weekend to go play with Hela.

I decided that I should really use the time to get on with the last of the big wiring jobs, so wire st*****rs in hand I set forth…

First job was to finish wiring up all the dash switches, which have all been done on the main dash including the dual intensity lighting circuits. The lighting for the lower dash switches (courtesy lights and heated seats) needs to be still added. All the extra circuits work (front heated screen, auxiliary cooling fans, courtesy lights in both footwells, front fog lights (more on those and the DRL set up at a later date)). Thanks again to the team at Car Builder Solutions for all their help and patience with me whilst I worked out what I needed.

Second up was those beautiful gauges from
Speedhut Custom Gauges in the US. So easy to fit. Nice and shallow too. My only trouble was working out how to wire them up to the Speedhut dimmer module. For the non-LED gauges they make, Speedhut can supply a wiring harness that links them all in series. Sadly they don’t make a similar harness for the LED gauges and they all have a custom plug on the end of the OEM harnesses. Linking all the wires (three to each gauge) could be achieved using a good old fashioned bus bar but they are very bulky for behind the dash.

Thanks to the InterWeb thingy I managed to find a nice elegant solution - an 8-way Wago connector. It is designed to cope with vibrating environments and typically is used with a single core wire - the gauge harness is of course multi-strand. Solution - a trip to Valhalla (my garden workshop - can you see a theme here?) and grabbing some ferrules. Easy peasy lemon squeezy. Wires routed, stripped, ferrules fitted and pushed into the Wago connector. Each connector will then be bonded to the back of the dash and the wires tidied up as normal.

So, most things have now been done on the dash itself and all the wiring completed. Thanks to those on the GD forum for their support with getting over little the slump - two days of cracking on seems to have been what the doctor ordered.

I still have some wiring left to do - finish off all the DRL module wiring behind the dash, make a couple of harness bits at the front for the fog lights, sort out the EPAs and ECU feeds (wiring done - just need to add the end connectors) and put the wiring in for the radio and screen, but I’m a lot happier now.

And now the reason for the title - I closed the evening off by firing up the dash and checking all the circuits. It was so very satisfying to see the gauges fire up, do their dance and settle back ready for the various inputs in due course. What a great start up routine that will be! So I thought a little video would be in order showing that sequence - hope you like it.

10/07/2026

A nice little home brew DPDT car instrument switching module. Boards courtesy of a Chinese manufacturer to my design, rest by me.

10/07/2026

Shedding a little light on matters

Well my little circuit boards arrived from China today along with some of the smallest electronic components I have ever seen! Think half a grain of rice in terms of size. A bunch on 1N4007 diodes and some 1.5k ohm resistors.

Like the little gnome I am I shuffled off to my workshop and dug out my soldering iron, flux and a bleeding great magnifying glass with a light on it (thank you GloForce for your units which initially I bought for playing model railways!).

Fly leads attached and components mounted, it was testing time. It worked - she’s alive (cue Weird Science music). The back lights come on dimly with the sidelights and then strengthen when the switch is pressed. It’s deliberately subtle - I could ramp up the resistor to get a more dimly lit “sidelight” mode but I am happy with what I have.

Tidied the whole lot up with some glue-lined shrink tube and I think they make a nice tidy little unit. Well worth the time and the eyestrain IMHO.

See what you think?

08/07/2026

Resting on my laurels?

You may remember that I have been toying with the idea of an armrest / centre console for the back of the transmission tunnel to (a) house a mobile phone charging pad and (b) provide a tiny bit of storage for a few bits and bobs.

Well, in one of those idle doomscrolling moments last night I came across a Subaru Impreza arm rest lid on Fleabay. It’s about the right size and has the hinge and latch already attached. I am sure I can modify / butcher the pad etc to make it fit the dimensions of the transmission tunnel and can use my O level woodworking skills to build the lower half of a box from mdf and fibreglass. I can add a metal latch plate at the front to work with the lid catch and a separate pad at the rear to cover the hinge with push down clips to lock it in place. It will then be up to Robin and team at Intatrim to make it look nice or tell me I’m a complete idiot! Only time will tell…

Anyway, here’s a picture of the lid and I will update everyone once I’ve finished with the router / saw and the fibreglass and filler.

05/07/2026

And even more electric trickery!

Not much to update on except I am still finishing up the joy of the wiring. Having proven all the circuits with the help of Captains Bodge and Fixit, it has been steady but slow progress in converting all the Heath Robinson connections to proper reliable links and putting the finishing touches to the dash loom.

Where possible I have chosen to pick up feeds from the GD loom, and then extended them with matching wires to terminate in the 2.8mm connectors on the back of the Car Builder Solutions switches.

All terminals have been insulated using adhesive lined shrink tube and each leg has been wrapped in automotive quality braided sleeping. The ends of the braid have then been finished with more shrink tube and each “leg” labelled with its purpose using shrink tube printed labels.

For switches, I have also added a pin number to each wire (B1, B2 etc) so that when the dash comes out for trimming we know where each and every wire goes back to. Hopefully the switches will only need their illumination feeds removing since the DPDT switch block is independent to the switch but it’s better to be safe than sound.

Talking of switch illumination, watch this space for a little bit of fun / total overkill. Having worked out (with some advice on the use of diodes) the circuit for making the switch lighting change intensity depending on whether they are open or closed, I wanted to try something a little more permanent looking than a bunch of electronic components soldered together and held together with sticky backed plastic (those who know, know eh?). I found a natty little piece of free software that allowed me to design a tiny little circuit board that takes surface mount components and am currently awaiting a shipment from China of twenty little boards that cost very little. Much easier than DIY with veroboard and the like. I will put up a separate post when they are done and dusted.

So the dash loom is nearly done. I’ve also mounted the screen and wiring for the stereo screen and will again post a separate piece on that. In addition, I spent two or three nights rewiring the heated seat circuits to fit the car properly (will do a post on that too) - it’s really clever (to this Luddite anyway) how they get them to have two heat settings using parallel or series wiring of the seat pads. Back to ‘O’ level Physics to remember all those calculations and wiring diagrams. The pain of it all!

Getting there but at the moment it’s all in twenty to thirty minute blocks in the evening when I’ve finished work and my domestic duties, so it’s frustratingly slow progress. Hey ho - Rome wasn’t built in a day as they say.

Here’s a picture of the dash loom as it currently stands with all my OCD work to date.

14/06/2026

Carry On Screening anyone?

Just a little update after a busy weekend and an awesome trip to Glyndebourne last night to see Tosca.

The real dash is now test fitted and all is well. Some trimming needed around the scuttle edge to allow the gauges and tell tales to clear, but not much else worrying me at the moment.

Took the time to test fitted the screen for the stereo - a lovely Pioneer unit with remote screen and a head unit which goes in the boot. The screen fits nice and snug up against the bottom of the long dash and leaves just enough room at each side I reckon to fit the heated seat switches and the courtesy light manual switch. I will probably put them on the curve I’ve marked with the chinagraph pencil. Lower row of gauges still clearly visible and I can reach all the other switches from the driver’s seat.

Next step is to lay down a sheet of 9mm marine ply on top of the tunnel to allow me to (a) route the cable from the head unit to the boot, (b) speaker cables perhaps coming back the other way and (c) maybe even a pop out cup holder in the passenger footwell. It also allows me to screw down the screen bracket without breaking through the transmission tunnel. That said there will be a rather large hole through it for the gear lever so perhaps I’m overthinking it for a few rivnuts?

Address

Sevenoaks

Website

facebook.com

Alerts

Be the first to know and let us send you an email when A Viking’s Journey into GD MK4 land posts news and promotions. Your email address will not be used for any other purpose, and you can unsubscribe at any time.