Trailers are notorious for electrical problems.

They’re not used very often, sit in a weather most of the time, and are usually wired up pretty badly!
This one had a problem where everything tested out ok, but it would keep blowing the tail light fuse on the tow car.

The lights had mostly been changed to LED so they don’t use much current, and several workshops had tested it and found no fault - but it still kept blowing fuses!

I checked that all the pins were wired to the correct circuits, and that none of them were shorted together.

I then plugged the trailer into the car, and found that everything worked fine!

It was then that I checked for voltage between the car’s ground and the trailer chassis - and found 12v!

So, when the trailer is tested it’s fine, but if you connect it to the car’s tow bar it then shorts out to the car’s ground!

It was the tail light circuit that was connected to ground on the trailer, so I started with the number plate light (the only non sealed LED light left on the trailer) - figuring it might have a damaged wire or bulb holder.

What I found was that one of its terminals connects to the trailer chassis (so you can just have one power wire and use chassis ground) and that terminal had the power wire on it instead of the ground.

It was just a matter of swapping the wires over and now there’s no more blown fuses!

It’s actually sitting on a trailer now!

The roof is mostly done, so I just need to finish the front canopy, cut the carpet to size, install the wiring, sort out the steering, bolt the engine on, and fix up various bits of damage I’ve found on the hull. Easy

LEDs have gradually been getting brighter and more efficient - but they haven’t really been good enough to replace normal halogen or HID lights for high power torches or vehicle headlights.

I hadn’t thought much about using LEDs for serious lighting applications until I saw one of these in action: http://www.jaycar.com.au/productView.asp?ID=ST3371&CATID=21&form=CAT&SUBCATID=649

It’s not cheap, but has enough light output to be used as a headlight on a motorcycle. LEDs use much less power than normal halogen lights, which is a real advantage on an electric vehicle.

After doing a bit of research I found some massive LEDs complete with reflectors and driver circuitry, so I bought four to test out.

Even powered by a half dead 9v battery, one of these is easily brighter than a Dolphin torch, with a much wider light output.

I mounted all four on a piece of polycarbonate sheet and took them out to compare against the car’s headlights.

This is the car headlights on high beam:

And this is the LEDs (same exposure settings on the camera):

The aim is slightly different, and the LEDs are only on the right hand side, but you can see that they are bright enough to realistically use as headlights.  Note the house in the distance is similarly illuminated by both lights.

I will be doing some more testing and comparisons, and will hopefully be able to run an LED headlight on the next electric motorcycle!

This bike had been sitting around for a while, and wouldn’t start.

I checked spark and found it was fine, but no fuel was making it to the engine - which is usually a blocked needle valve in the carby.

After taking the carby apart I found it was completely full of white corrosion, which explained the fuel blockage!

Most of the parts could be scraped clean, but some of the passages needed to be drilled out, and then all parts soaked in a caustic soda solution to get it back to clean metal.

It all came up pretty well and after a bit of a tune the bike ran really well

The next step was to replace the rear tyre tube, which wasn’t too hard once I found some tools to use as tyre levers!

I’ve been helping with an electric gokart project, which was initially to test out the drive train for another electric motorcycle.

The performance was very impressive, so it is now being developed further to establish a viable electric racing gokart design.

We’d changed the motor sprocket since its last run, to get some more top speed.

The initial acceleration is not quite as neck snapping, but it winds out for a bit longer now.

We also installed a dashboard to keep track of power consumption so we can work out what size battery pack a race kart would need.

Against 100cc 2 stroke race karts we have better low to mid speed acceleration, but lack a bit of top speed at the moment - at the “Butterfly Farm” track we tested at. Cornering is good, but the kart is carrying  a lot of extra weight compared to a petrol one. Better batteries would improve the weight a lot.

The next step is to try some higher performance batteries, and adjust the gearing further for more top speed