Wiring

Finally made a start to the wiring on the car over the last few days.

Since I started, I eventually tracked down a PDF wiring manual http://www.jtresto.com/e21/ETM_1979.pdf, but initially I went through with a battery charger and connected individual pins to determine which wires for the rear lights were which. I was a bit hasty removing the original wiring from the car so this was cut off at the base of the back seat. Once I'd determined which wires were for what, I extended them (with the original loom, which I still have, as I figured I'd need the connectors - thank god I did that - more on that later!). I am going to run the relays for everything in the car at the passenger footwell. I'll be putting a bar to stop passengers from being able to kick anything loose. The Battery will be in the boot and the master switch will be in the centre console near the hand brake and shift lever so either the driver or passenger can turn it off.

I dug out the engine bay loom and untaped it, then seperated out everything except the two headlight and indicator loom wires, shortened the ground wires and put terminals on them, and then extended this wiring and ran it also into the footwell.

I joined the front and rear indicators, and parker wiring together, and tested that I had all the things I wanted (I don't think I need a horn, I don't have a horn switch anyway) --> Headlights, Parkers, Indicators, High Beam, Reverse Lamps. I also ran the wire to the footwell for the rear demister. I don't know if I'll need it but it's easier to run the wiring now than to leave it until later and have to find/run it.

Then (and this is where keeping the connectors comes in) I tried to work out how the combination switch (High/Low and Left/Right indicators) works - turns out there is a (very proprietary) 12 pin plug (approx) and inside this plug these switches have both their pins wired; so you need to find BOTH matching pins to be able to use the switch. It's probably not a massive surprise for those of you who have done this sort of thing before, but it sure makes using a multimeter to work out which wires are used very time consuming - in the end I gave up and tracked down the wiring diagram mentioned above.

I've also cut back the loom for the hazard switch, and will be connecting that as well; it will get it's power (fused) from in front of the master switch, so the hazards can still be run in any incident where the rest of the power has to be cut off. The fuse should protect it from any other dramas though.

I taped an E-series flasher unit to a couple of relays, and have wired up the relays for the indicators/hazards, now I have to wire the indicator light into the hazard switch and connect it and the combo switch up for a test run. Once that's done, lights are practically done (N.B. I still have to work out the dash lamp wiring, but I'll treat that as a different job I think!)