TC Wiring - Addition of Fuses

The following is from Nicholas Fitzhugh on the mg-tabc group on 9th June 2016.

~~~~~~~~~~

Here is a summary of what I will do on TC7142 as a consequence of the feedback:

1. Disconnect the live inspection socket on the dashboard, leaving the two plugs installed to fill the two holes. Members have experienced the live socket shorting. Looking at the mechanical arrangement of these sockets I can see that the insulation and separation is far from ideal.
2. Install an 8 way spade fuse box located on the back of the tool box under the dash. This will be convenient for intercepting wires from the dash which route through the firewall. As I do not intend to fit the under-dash board the fuse box will be readily accessible.
3. Use solder tags for the fuse connections covered/insulated with heat shrink insulation. I can solder the ends connecting to the fuse box prior to fitting the cables to enable me to avoid doing this in a cramped/confined space. I am told that crimping can be unreliable and wires can fall out and may themselves cause a short. The use of heat shrink fitted after the soldering means that the whole of the connector can be covered just allowing a gap where the connector pushes onto the fuse box.
4. Use the fuses specifically for the long wires that run along the chassis as they are more likely to suffer mechanical damage or loose connections in the end unit (rear lights in particular) which can also cause a short.
5. Fuses will be used for: Starter motor to ammeter, head lights main beam, head lights dipped beam, Sidelights, rear lights, indicators RHS, indicators LHS and horn. This makes 8 in total.
6. Use a 30 amp fuse for the starter motor to ammeter circuit. Other fuse ratings TBD.

Further to my report sent earlier today, I now find that it is possible to buy push-on preformed insulation which should be easier and quicker than using heat shrink. - Nick

Forgot to mention before that I will install a cut-out on the battery so all power can be cut off at the turn of a knob. Not strictly to do with fuses but related. I have also since been advised to ensure adequate earth points throughout the wiring. - Nick

~~~~~~~~~~

See also http://ttypes.org/ttt2/hybrid-wiring-scheme-for-an-mg-ta

Also, Madhuparoor commented that crimping works well if you use the correct crimping tool and matching ferrule to the conductor wires. He also comments that solder spoils the structure of the copper conductor and can break with vibration.

Return to Notebook