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Welcome to the Carreg Motorsport web site. My aim is to provide quality motorsport electrical services to the club competitor.

My work is aimed fully at the club level competitor so if you’re looking for a WRC or F1 wiring harness, or the headlights fixing on your Mondeo then I’m not for you (but can recommend companies at each end of the spectrum). However, if you need custom wiring work , from an experienced ‘tech’ with decades of motorsport experience (as a competitor and car builder), then please look at the services I provide.

I work from a small unit near Llanelli but I’m happy to travel for small jobs. I also have a well equipped workshop at home (with a lift) so can handle most work effectively. Here’s what I’ve been doing recently:

This car has challenged me from Day 1! So today I'm going through the setup again on the Motorsport Electronics Limited ME360 to make sure all is OK for it to run. The throttle position sensor is all configured and working well, showing voltage changes as expected. The 2D table / HRT shows everything as it should be, but I'm not getting a TPS percentage figure. It must be me doing something stupid but I can't see it!

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I really like the new business key fobs. Great service from fobkeyrings.co.uk - thanks!

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What was supposed to be a morning of testing and ECU setup (laptop and coffee ready) hasn't gone well! A firmware update on the ECU appears to have crashed and now it's not responding 🤦‍♀️

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Yet more Micra challenges. The O2/Lambda sensor was jammed against the engine mount (and yes the wiring was damaged) . There is no wonder this thing didn't run! I managed to remove the sensor (in bits) to fit a proper Bosch Wideband sensor but now have the dilemma of how to fit it. I have a 90 degree fitting but that won't wind in as it fouls the other downpipe. Looks like the manifold will need to come off 🙁

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Monday challenge 🤦‍♀️

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Carreg Motorsport️ Updated their cover photo. 2 weeks ago

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I'm looking forward to having this Radical Clubsport in for some work. I did a lot of wiring on it a couple of years ago but now it's having an ECU / wiring swap.

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Great to finish (almost!) this today and pass it back to the owner. It's a replica of a 1931 Ford Model B I think. It's old school with a big V8 (with a distributor!) and classic gauges. But running it all is a Hardwire Electronics PDM25 (which will be hidden behind a panel). Big thanks to George at Hardwire for helping me out with a software glitch and some stupidity on my behalf on a Saturday! There are some other modern bits in there (LED rear lights, GPS speedo gizmo) and the PDM was the perfect choice to integrate these with the older stuff and classic switchgear. I'm waiting for the owner to fit the fuel tank and wiper motor (with its 7" wiper blade!) so I can finish off the wiring and setup. My unit looks like my toolbox has exploded so a tidy up is the Monday morning job!

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Great to see some decent power from our Clio 197 RS yesterday at Mosley's Rolling Road & Garage Services.! The car is fitted with: DTAFastT4 ECU, Hardwire Electronics PDM28, Blink MarineCan keypad, and Race Technology Ltd Dash2 Pro (all connected over CANBus) . There's also a Jack Webb Motorsport LifePo battery and Cartek Motorsport Electronics battery isolator. There's not a lot of Renault electrics in there now 🙂 Dyno figures - https://docs.google.com/spreadsheets/d/e/2PACX-1vRIZ987znSulLHhOIRT_oo4iCVrjqkZN6Pd0EOO76JslWhvrZF5dgpn-Buc9xlkJNIvEJzUSPVLHBQm/pubchart?oid=36578149&format=interactive

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I'm really pleased the way this is working out. Hardwire PDM 28, Blink Marine Can Keypad, Race Technology Dash2Pro and DTAFastT4 ECU, all connected via CANBus. I have a little bit of tidying up to do (waiting to weld the bracket for the PDM to the cage) then it should all be done .

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This isn't what I usually do but it does take me back a few years to dashboards filled with 'clocks'. Not a digital dash or CANBus (well not quite true) in sight! As old school as this is and it suits the car perfectly, there will be a Hardwire Electronics PDM tucked up under the dash to control everything 🙂

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The logging feature in the Hardwire PDMs is great for removing some of the guesswork in setting everything up. The graph is a log of the starter solenoid current and voltage on starting. The current peaks at just under 23 amps for about 20 milliseconds, then drops to around 7 amps after the solenoid has 'pulled in'. I can now set the 'fuses' appropriately (second picture). https://www.hardwire-electronics.co.uk/

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I do like a CAN keypad 😁

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CAN keypad fitted as part of the upgrade to a Hardwire Electronics PDM. Wiring is simply 4 cables so this tidies up the wiring and keeps things simple. The complexity is in the hardware, software and setup.

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People ask me why I advocate PDMs but don't have one in our race car! So here we go! It was always planned and the switch over from fuses and relays will be relatively easy as everything is documented. Hardwire PDM28 ( a bit over the top for this but plenty of room for expansion), DTAFast T4 ECU,and Race Technologyy Dash2 Pro. All British companies - trying to have as little French stuff on the Clio as possible 🙂

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I managed to spend some time on this Micra today - the DTAFast T2 is in and mounted (I've left the harness long to make sure we have clearance around the heater) . The engine harness is in and just needs a couple of bits sorting (coil pack and grounds to the head). The next job will be to connect the ECU/Engine harness to the standard (modified) harness.

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I've been quiet on the updates as we've been busy competing. The Clio 197 RS Cup went well at Pembrey Sprint on the weekend despite an 'incomplete' map.

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Not my usual kind of job! A replica of a 1932 Ford Type B Hotrod. Somebody has wired the dash and somebody else has run the wiring harnesses. I 'just' have the job of wiring it all in! A bit of a headscratcher!

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Carreg Motorsport️ Updated their cover photo. 3 months ago

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Carreg Motorsport️ Updated their cover photo. 3 months ago

Carreg Motorsport️ Updated their profile picture. 3 months ago

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Loving the new Harness design software! It looks like madness in this view but it creates a superb spreadsheet with everything documented, each individual component detailed and you can build a parts list, costings and everything. So much easier than trying to build this in a spreadsheet. This is the whole ECU / Engine harness for a competition car, drawn in less than 2 hours.

Happy with that although it has taken a whole day! All ECU connector terminals and the three connector blocks replaced. All wiring checked for water damage. Bulkhead fitting installed (not heat shrinked yet). All bench tested - last job will be to test on the car.

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Absolute pain in the a#£e job. Water ingress to the ECU on a rally car. ECU has been repaired by #dtafast and I've got the wiring harness to repair. I'm fitting a proper bulkhead fitting at the same too so it's a bit of a challenge

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I might be away on holidays but I'm in the middle of a sprint and Hillclimb car rewire / new ECU. So, I'm sitting, relaxing and configuring the engine sensors 😁 The Motorsport Electronics Limited MEITE software is great once you get into it !

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The joys of configuring a Race Technology dash!!

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We had a nice Fiesta road rally car in today - just a social visit but it does need some tidying of the wiring 😁

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It's been a hot day but I made some progress on roughing in the harness for our Clio Cup 197 'build'. The car is having a Motorsport Electronics Limited ME360 ECU (lovely bit of kit and at a very good price point! No PDM (fuses and relays) but full CANBus dash setup.

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Good to see a friend / customer trying hard at Gurston Down Hillclimb!

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Nice little bit of progress on an engine harness for a Micra which is having a DTAFast T2 ECU. I'm fitting this in around other jobs / trying to get the new unit sorted so it's a bit stop/start -documenting everything is crucial! And yes the desk looks like it's seen some action!

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I'd have spent hours finding this leak without the (budget!) smoke machine!

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The (right) decision has been made to swap to an aftermarket ECU on this Micra rally car. It will be another DTAFast T2. The challenge will be integrating the ECU with the existing wiring as the customer wants to retain the stock chassis wiring (lights, wipers etc).

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8am start on this Micra. I've managed to bypass the immobiliser to get it running but it doesn't like it!

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It's time to have a look at this. Not running. Throwing a NATS fault 🤦‍♀️

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Carreg Motorsport️ Updated their profile picture. 6 months ago

Loton Park Hillclimb. Sunday 17th May 2026.

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Carreg Motorsport️ Updated their profile picture. 6 months ago

Great to have the first lift installed! Done professionally with the correct paperwork!

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Carreg Motorsport️ Updated their profile picture. 6 months ago

Darrell Morgan at Loton Park Hillclimb . 17th May 2026. Clio Phase 1 with Carreg Motorsport club rewire and DTA T2 swap. Darrell Morgan finished third in class (one of the most competitive classes) on both days!

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Great to see a friend / customer doing so well and the car performing so well too (despite gear selection issues!). https://www.facebook.com/share/18R5TkErn7/

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We're here and setup (almost) with the Clio 197 RS for our first visit to Loton Park Hillclimb. It's good to be out competing after a tough few weeks moving in to the new workshop and juggling work.

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Fuel gauge now working on this EP3 race car (full travel) and ready to go back to its owner. A relatively simple fix for once!

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It's the small things that make a big difference. Managed to get the new lock and box on the door today thanks to the welding skills of another Motorsport company 50 yards away. The old bolt and padlock were rubbish, looked like I welded them, and the bit on the frame came off with a good clout 😩 The doors on this place are typical MOD and are all steel and super thick. I feel more comfortable now!

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Testing this launch control sounded mad inside the unit! #dtafast

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Love this!

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Had this Clio back to configure the launch control and repair damaged wiring to a sensor. All went fine but when I ran it up to temperature there was a coolant leak! It was a mad panic to get it sorted before the owner picked it up, which meant stripping off the front panel, air filter and lifting the rad. Hopefully it's now ok but we will be parked near the car at Loton Park Hillclimb on the weekend so able to assist if there are any problems.

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Spot the fault! Civic Type R (EP3) race car in for some fettling.

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Well we have the keys to the new unit! There's a load of work to do - Security (digital mag locks, IP cameras and an alarm I think). Rewire (3 phase) Clean out 2 x 2 post lifts to install I've made a start by sorting out the sound system 🙂

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I'm looking forward to getting the keys for my new unit soon. It's 5 times the size of where I am now so, hopefully, I'll have enough space 😄 I'll have a couple of lifts to make life easier. And an ice cream van but that's a different story 😄

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