by Steve Finberg in the June 1994 RootesReview
The turn signals in my Series V Alpine were frequently flaky. Usually, all it took to solve the problem would be to slightly tighten or loosen the front lamp mounting screws. Unfortunately, this fix never seemed to last. The problem is that the ground return connection for the front turn signal light is made through some long screws passing through rubber bushings. These can shift making an unreliable connection.
The solution is to add a ground wire to each flasher light. It seems Lucas had this in mind as there is an extra molded nipple in the rubber boot on the back of the lamp. Remove the plug from the extra hole in the boot. Take a three foot piece of #20 stranded black wire and solder it to the ground contact inside the fixture. Route the wire carefully through the new hole so as not to interfere with the insertion of the wedge-based running light bulb. Now caulk and seal the wire and boot with silicon rubber (bathtub caulk). While you have the lamp apart, it is worthwhile to clean and inspect it for cracks. Repair with epoxy to keep the unit weather tight.
The new ground wire can be spliced with the headlight ground wire or, preferably, a new push-on connector mounted at the end with its mate mounted under the bonnet next to the headlight ground point. As an additional benefit, the expensive plastic lenses will last much longer since you will not have to over -tighten the mounting screws.