I’ve had an intermittent fault with the indicators on the BMW sidecar outfit for a while.

Problem with an intermittent is that when you go to fix it, it doesn’t appear or you do something, it disappears and you think you’ve fixed it but next time out it appears again!.

Anyway, this time instead of being slow and dim the both sides indicators stopped working altogether, pointing to a fault in the circuit before the switch, i.e. the flash-can, wiring to the switch or possibly the switch itself.

So after a look at the wiring diagram I saw that if I jumpered two of the can terminals I’d be putting power direct onto the switch, bypassing the can. This meant unplugging the can from its socket and connecting across the two terminals in the socket, 49 and 49a.

Once I’d done this I tried the switch and both sides of the indicators would light, showing that the switch was working ok.

Next suspect was the can and on a closer look I could see some heat distortion of the plastic case and there was a smell of burnt insulation, I popped the case open and it was stinking burnt, well it is about 45 years old so I don’t think I can complain too much.

So on line for a replacement can and find that they are priced at just over £52 each, seems it is an odd-ball unit that’s now obsolete.

Being of Scots blood and hence objecting to such a price I had a look around for an alternative,

I found that the official can had four terminals, power in, earth out, power out to switch and power out to warning light and while these come out as standard 6.3mm spades it does not fit the industry standard relay socket.

A little study turned up an equivalent unit at a price of £7.60 but it would not fit the BMW’s socket, it of course being designed to fit a standard relay socket.

This simply meant that I bought a matching socket to go with the new flash-can.

Before committing myself to wiring alterations I connected the new can with some short leads onto the old socket.

On the flash-cans each terminal is identified and anyway there is a DIN standard for labelling relay connections, terminal 31 is earth, 49 is power in, 49a is power out (in this case to the handlebar switch) and C is to the warning light and as these numbers are marked on the relay it was easy to cross connect.

So next was Ignition on and try the indicators and they are working beautifully so it was just a case now of changing the sockets.

There was a choice of two ways to do this. The new socket came with a set of contacts to be crimped onto wires and then inserted into the socket but I opted to just remove the contacts from the old socket and simply swap them into the new one.

The contacts are held in place in the socket by a locking tab and it is possible to retract this tab by careful use of a jeweller’s screwdriver, a look at the new socket and then at one of the new contacts and how it fits into the socket makes it clear how to do this.

Once a contact was removed from the old socket it was simply pushed into the corresponding place in the new one and then all that was left to do was put the new can into the socket, put it in place inside the headlamp shell and that was that!.