Ghost in Passenger side Blinker

photoer · #1 (**permalink**) 10-21-2007, 10:25 AM

The passenger side blinker on my 1974 Spider activates the running light and the side contour light. (seems impossible) With headlamps on it doesn't operate at all and the passenger side running light glows dimly. The wiring shows no signs of tampering and I am at my wits end. I cleaned relevant connections with steel wool and checked for good ground. I don't have a wiring diagram yet and would appreciate a suggestion how I might obtain one. Any ideas about the mystery?

**papajam** · #2 (**permalink**) 10-21-2007, 10:47 AM

Welcome to the Board, photoer!

Sounds like a ground problem. Don't assume that what looks like a good ground is a good ground. Ground screw connections are notorious for causing all sorts of electrical issues. They must be clean and tight!

If you send me a private message with your email address, I'll send you the wiring diagram.

crashmctavish · #3 (**permalink**) 10-21-2007, 02:40 PM

You have a double earth fault.

photoer · #4 (**permalink**) 10-21-2007, 04:17 PM

Thanks Keith - not really familiar with the term "double earth fault". Grounding points for the light circuits are feindishly difficult to locate on the 74 Alfa Spider. (am I missing something?) On top of my mentioned woes, I have no current going to the high beam on the passenger side. It has to be a simple problem to solve but I fear that the steering column lever cluster might be the culprit. I would like to solve it by logic alone. Pleas advise re. "double earth fault". Many thanks. Erik

**papajam** · #5 (**permalink**) 10-21-2007, 05:17 PM

double earth fault = two ground problems

There are four headlight fuses; one each for left and right high & lowbeams. If the left highbeam works, then the headlight switch is not at fault as the left and right circuits are split in the fusebox after the headlight switch. I'd check/clean/replace all fuses as necessary first. Then check for battery voltage and ground at the headlight connector.

crashmctavish · #6 (**permalink**) 10-22-2007, 08:13 AM

Headlight grounds are favourite, disconnect circuits at fuse box & test each ground (earth) with an ohm meter. You indicator/ running lights also have a ground fault. Current fails to travel round one circuit & then finds the shortest path. i.e. another cct.

photoer · #7 (**permalink**) 10-22-2007, 07:42 PM

Thanks for all your advice fellas. Much appreciated. I have fierce brush fire and then some issues at the moment (living next to Malibu). When the - ehm - dust settles, I will delve into my Alfa wiring again. Will report asap. E