1 st April 2017. I promise I won t add in any April Fool jokes into this report. But of course anything is possible! Yesterday, I only managed an hour on the MG, as I helped Jaymic with their stock take. I found that putting the stock take sheet quantities on to the computer was more tiring than working on the car, so today I ll have a rest and work on trying to finish the wiring on the car! should never be under stress anyway. Perhaps I am just an 'old fart' who doesn't want to move with the times! INDICATOR & HAZARD FLASHER UNITS These yellow and white wires are to go to the speed transducer that lets the engine know that the vehicle is moving. The speed transducer has two wires a black and a yellow wire. The wires on the MGRV8 diagram show that the white wire connects to the black wire! Believe it or not, the yellow wire connects to the yellow wire. Well done Rover. Does anybody know if the upper speedo cable from the transducer to the speedo head on the MGRV8 is available anywhere? To date I have not been able to find one either new or second hand. Also is the thread on the MGRV8 speedo cable fitting the same as the late date (1978) MGB speedo? I have now added the indicator and hazard flasher units to the row of relays for the headlight and horns. It is a long time since I have had to wire these up, so I looked at the base of both these alloy cases and they were marked B and L. Not remembering whether B was for Bulbs or Battery and L was for Live or Lights, I thought I had better look it up. It is, B = Battery, L = Lights. RADIATOR CAPS RELAYS I have been looking on the internet to try and get my head around relays with diodes incorporated into the relay. I found the following site which gives details of all sorts of relays that are available: www.12voltplanet.co.uk/relay-guide.html WIRES SOLDERING OR CRIMPING A V8 Register member sent me a link to the website about crimping terminals and how it now appears to be better to crimp a wire than solder it. www.v8register.net/protect/files/150730-crimping-tips.pdf I am still not convinced. The problem with crimping is that it is possible, in damp situations, for the terminal and wire to corrode and build up a high resistance in the joint. The other problem that is mentioned by Holden's is that the solder can creep up the strands of the wire and can cause the wire to break if stressed. Wires I could not remember why I had taken this photo, but now I remember. Car Builders Solutions sell rather nice stainless steel radiator caps at various pressures: 4psi, 7psi 10psi 13psi, 15psi and 20psi. The higher the cap pressure V8 Register MG Car Club 170401-V8-restoration-Mike-Macartney-Report-130 1
the higher the boiling point of your coolant in your radiator. How much does the pressure raise the boiling point? Well, it's about 2-3 degrees for every psi that we increase the pressure of the cooling system. I went for a 15psi cap. Before I attempted wiring the relays, that are fitted to the fuse board, I got on with wiring up the relays for the headlamps, horns, indicators and hazard lamps. BACK TO THE WIRING A lot of wires and I have still got to wire in the main relay, starter relay and fuel pump relay. I am having second thoughts about leaving the polished stainless steel mounting plate for the fuse and relay boxes. I m now thinking it looks a bit tacky, perhaps it would look better in semi matt black? As the relays had Grow'd like Topsy I needed to make a plate to mount them all. V8 Register MG Car Club 170401-V8-restoration-Mike-Macartney-Report-130 2
At this stage I am starting to think Why didn t I stick with the standard MGB loom and fuse box and just add the wires I needed for the MGRV8 injection system! It would have certainly made my life simpler. Once you start fitting relays they start to multiply like rabbits. I ve added the change over relay for the daytime running lights and the relay for the radiator fans. This seemed a good idea at the time. I had these plastic connectors that I could use to temporally connect the wires and mark where they went with labels. Later I thought that I might as well use the connectors in the wiring scheme instead of the multipoint connectors. That is why I have added heat shrink to all the connectors apart from the headlamp main beam terminals. Before I started fitting the wires for the relays I thought I had better mark up the rear of the fuse board and relay panel with what did what and how the orientation went with the relay terminals. V8 Register MG Car Club 170401-V8-restoration-Mike-Macartney-Report-130 3
Now there are some jobs you feel that you should never have started. This wiring job is becoming a marathon! Although I think I am going to fit the radio in the glove box, behind the glove box door, I have installed a fuse down by the radio aperture in the centre console and taken another white and green fused wire up to the glove box area. The ignition switch had been changed at some point in the MGB s life and fitted with bullet connectors. I changed these for one block connector. Wiring the relays was a pain; the wires had to first go through the plastic retainers. V8 Register MG Car Club 170401-V8-restoration-Mike-Macartney-Report-130 4
At last the fuses and relays were wired up and ready to see if the fuse and relay board would fit into the bulkhead on the right hand side. OK then, where do I start? Time for dinner, I ll come back to the wiring tomorrow. Just in case any of my terminal blocks touched the bulkhead I insulated them with heat shrink and tape. It s a lovely sunny morning out there, do I really want to go out to the garage and get on with the wiring, when I am quite happy in my office, writing the reports? V8 Register MG Car Club 170401-V8-restoration-Mike-Macartney-Report-130 5
The problem is that with so much wiring to do it makes photographing what I am doing rather boring as most of the photos look like a rats nest of coloured wires. At this stage I am running out of slightly interesting photos to include in my reports. This photo shows the new indicator stalk switch fitted and the various earth wires connected with soldered on ring terminals to the steering column mounting brace. The incorrect stalk switch was returned for credit and the new old stock one fitted. If buying a new stalk switch from ebay, do check that the diameter of the clamp is the same as yours before paying for it. Unfortunately, I forgot to write in my book the diameter the clamp is meant to be, I am not going to take the cowling off again just to measure it sorry. Another job I decided to do, after much thought, was to paint my bright and shiny stainless steel mounting plate for the fuse and relay boxes, semi-matt black. I also widened the gap for the wires to pass through to the inside of the car. As I had decided to split the green, ignition live wires that all come from one fuse, into a number of fused circuits, for different components. I needed to attack the dashboard wiring again. After a lot of snipping, wire stripping, crimping and soldering, the fuse box and relay boxes are nearly ready to fit and connect to the wires from the various looms, or should I refer to the looms, in their present form, as a rats nest! V8 Register MG Car Club 170401-V8-restoration-Mike-Macartney-Report-130 6
The next job on the list was to find homes for all the wires that either connect to the rear loom, dash loom, front loom, engine loom or the fuel injection ECU. All the wires now have homes, but what do these five do, that have nowhere to go? I know the White/Red wire goes from the ignition start position to the starting relay. The four green wires I will have to trace with the multimeter to see where they come from. The rear loom was connected with rubber bullet connectors so that this rear loom could be pulled out of the car if required to do so in the future. If I had used a mutiterminal block connector on this loom you would have to cut the connector off, to get the loom through the rubber grommet in the panel behind the rear seat. That s one green sorted, it comes from the hazard light switch and goes to the indicator flasher unit. V8 Register MG Car Club 170401-V8-restoration-Mike-Macartney-Report-130 7
Let s have a break from wiring and go into some history on the MGB. I had another email this week from a regular reader asking why I had fitted the indicator and side lamp the other way round to the way his MGBGTV8 has them fitted. After some detailed research I can tell you that 95% of the entire chrome bumper MGBs have the lights fitted the wrong way round! Not many people know that, as Michael Caine would say. History is a funny thing. Facts tend to get over simplified, written over, or forgotten. No one man ever created a commercially successful car all by himself. John Thornley, Syd Enever, and Don Hayter all worked together to make the MGB happen. After sketching out the design of the car they passed the basic design to the various staff in the design and development drawing office for them to come up with designs for the various parts of the car. The lighting design and development was passed to Ivor Blink who was a new employee in the company, previously having worked on the Blink Microscope. He remembered what his bosses had said about using as many in use components as possible. To that end, he used the combined Lucas front side and flasher lamps, drawing them with the amber indicator to the outside of the front wings. Much later, when the drawings were sent down to the tool room for the steel dies to be made for the lower front section of the front wings, the foreman, Dai Hacker, directed one of his tool makers to make the cut out for the indicator side lamp unit with the side lamp on the outside. This mistake was never noticed and so all the chrome bumper MGBs manufactured had the indictor side lamps the wrong way round to what was originally intended. With the relay block I was having problems working out which wire was which when the relays were fitted in the passenger s side footwell. I decided to remove the block again and identify the wires with different coloured tape. Red was the fused power to the relay, White, I used for the load and grey for the switch wire. BACK TO THE WIRING The road speed transducer came with a plug female socket. As I had no matching male plug to fit I replaced it with a male and female block connector. All marked with coloured tape and ready to fit back on the MG. I hope that by the end of the next report the wiring will be finished and hopefully work! You can email me at: mikemacartney@btconnect.com with any hints or tips you have, which may help me, or other V8 register members. 9 th April 2017. V8 Register MG Car Club 170401-V8-restoration-Mike-Macartney-Report-130 8