I am completely baffled by the latest electrical problem on our 70 RR. Went to the local track but rained out (it is the wet time of year here). Went to leave, turn on lights. Nothing but headlights. Drive home anyway, what else to do. Decided to do some trouble shooting. There are two hot leads to the headlight switch. One is 16 ga, the other is 18 ga (both seem light to me but that is a different discussion). There is 12 volts at each. The 16 ga I think drives the headlights, the 18 ga drives everything else. When I jump from the 16 ga terminal in the connector to the taillight terminal in the connector, the running lights all work. When I jump from the 18 ga one that is supposed to drive the running lights (it comes directly from the fuse block terminal marked stop/tail) nothing. Even the 12 volts go away when it is jumped together. When I use the 16 ga wire to jump I still get 12 volts at the 16 ga wire and the lights work.

To make it more frustrating, the brake lights also do not work. Even if I pull the wires off the brake light switch and jumper them together, no brake lights. There is 12 volts at the wire that is supposed to have it. The turn signals work fine, so I do not think it is the turn signal switch but ???.

I have removed and reinstalled the fuses in the fuse block, so I do not think it is corrosion there but maybe?? I am getting 12 volts but perhaps under load the resistance is too high due to corrosion? We are ground zero for corrosion here.

We have three British cars, all older than the 70 RR. Their electrical systems are 1/8 as complicated (the entire car fits on one page)and work better. This is not the first time I have been tempted to gut the entire electrical system and streamline it with Lucas fittings I can trust.