Fitting a pair of USB sockets and fixing the horn.
March 13th 2020
Even though I'm trying to keep the Morris as original as possible, even down to the lack of seatbelts, sometimes you just have to install a couple of modern conveniences. In this case I'm talking about USB sockets!
As I'm planning to attend a few classic car events around the country this year, I need some way of powering my phone which I'll be using as a satnav. Also I have decided to fit a small radio discreetly under the dashboard to keep me entertained on those long slow journeys.
If the car had a 12v 'lighter' socket then I could have just plugged a USB adapter into that but alas it doesn't. I considered fitting one but decided to just skip the middle man and wire in a pair of USB sockets directly. This involved purchasing a DC-DC converter and an inline 10A fuse, along with a length of wire.
I started by soldering the fuse holder onto the positive input wire and then crimping on a ring connector. This will be attached to a suitable 'earth' point on the chassis. Remember that this car is positive-earth so I can take my 12v feed from any nearby earth point.
Transferring everything over to the car, I found a suitable mounting point tor the converter box. Using some double sided mounting tape and a zip tie I attached it to a discreet place under the dashboard on the passenger side. The next job was to take the black negative wire and neatly route it along the underside of the dashboard and through a convenient hole in the bulkhead (firewall), close to the fusebox. The end of this wire was then connected to the bottom terminal on the fusebox which permits a path to negative only when the ignition key is on. Having the converter powered continuously when the car is not in use probably isn't the best idea. Partly for the safety aspect and partly due to parasitic drain of the battery.
Finally I loosened a nut near where I'd mounted the converter box, sanded the paint off around the hole and bolted the positive feed wire down. The moment of truth arrived and I connected my phone to one of the USB ports, turned on the ignition and as if by magic (but more likely by science), my phone started charging!
Now that I had two working USB sockets, I fitted a small retro-looking radio under the dashboard. The radio has an internal battery which is kept topped up by a USB input from one of my sockets. This allows me to either listen to FM radio or to stream music from my phone via bluetooth. They didn't think of that in 1954 did they!
Every step of the job is reversible if I ever wanted to return the car to original condition, I never make any permanent changes such as drilling new hols etc.
Now onto the next job. A few weeks ago my horn mysteriously stopped working and believe me, you need a working horn around these parts! If the fault is with the horn itself then unfortunately it would be rather expensive to replace it like-for-like. The later type horns are still quite inexpensive but this car has an earlier Lucas 'Alette' horn which cost quite a lot to replace. Still, let's dig in and see what we can find. I first undid the retaining screw on the horn button and prised it out of the steering wheel. Not only was it receiving 12v from the battery but a continuity test revealed that the horn push was working fine. Ok, onto the horn itself...
I loosened the two terminals on the back of the horn and removed the wires before attaching my own. Touching the other ends directly to the battery terminals produced a loud beep from the horn. That's a relief! At least that wasn't the problem either.
Then I connected my multimeter to the horn wires and pressed the button on the steering wheel. This produced a constantly wavering voltage between about 0.5v and 9v. Definitely something amiss there. I connected only the positive wire to the horn and ran a new negative directly to the battery and everything worked perfectly! The horn produced a strong beep when I pressed the button. Ok so the fault must lie on the return path to negative which goes via the fusebox.
After a little exploratory probing I traced the other end of the negative wire where it entered the fusebox and a little bit of continuity testing showed me exactly where the fault lay. The fuse in question was very tarnished, as was the holder which resulted in a very weak and intermittent signal. I removed the fuse and cleaned it up with some sandpaper. The same was done to the fuse holder before reinserting the fuse and giving it a test. Everything worked perfectly and my horn is sounding stronger than ever! I think this calls for a nice drive out to North Wales in the morning...
