Are Lucas electricals as bad as everyone says?

A few weeks ago, I reached the point in the resurrection of my 40-year-dead Lotus Europa Twin-Cam Special where the drivetrain was finally back in the car, and the intake, exhaust, and coolant systems were buttoned up. The time had come to drop a battery in, twist the key, pray to The Automotive Powers That Be, and check for oil pressure.

As anyone who owns a long-dead British car with a Lucas electrical system would, I had some concern that I might “let the smoke out of the wiring harness,” as they say, particularly since there were several unsecured wires dangling ominously from under the dash. I looked at the wires and figured out that two of them were related to a makeshift push-button that someone had mounted to the left of the steering column to fire the horn, which itself seemed like an ominous harbinger of problems with the car’s electrical integrity. A third wire was a stray spade connector; I would need to spend some time to determine where its home was.

This looked scary, but two of them were just jury-rigged horn wires.
This looked scary, but two of them were just jury-rigged horn wires. Rob Siegel

I temporarily secured the wires to be certain they wouldn’t short something out. Then I muscled the battery from my BMW 2002tii into the Europa’s crevice-like battery tray (incredibly, it turns out that the two cars take the same sized battery) and connected the first the positive and then the negative battery cables. I didn’t see any sparks or smoke, so I got into the car, held my breath, and turned the key.

Something amazing happened. It wasn’t that the starter cranked, because it didn’t. (I’ll get to that.) The amazing thing was that, when I rotated the key, the wipers began arcing purposefully back and forth across the windshield. I know what you’re thinking: This is classic Lucas electrical system cross-wiring, where cranking the starter doesn’t crank the starter but does fire up the wipers. Nope. Dead wrong. What happened was simply that, for all these years, the wiper switch—a stalk on the steering column—had been sitting in the “on” position, and when energized by a battery and a key turned to the accessories position, they simply worked.

I was, to put it mildly, astonished. The fact that the starter didn’t crank was irrelevant. Gee, I thought, I wonder what else works.

I hit the hazard switch and walked around the car. All four directional lights flashed. Then I independently tested the left and right directional with the stalk. Check. I turned on the blower fan. It worked. I clicked the power window switches. Both windows rolled up and down. Although the headlights didn’t turn on from the dash switch, they responded to pulling in the stalk to flash them.

Holy cow. This is “Prince of Darkness” Lucas, manufacturer of electrical systems so notorious for problems that there are entire websites devoted to Lucas jokes. I was so astonished that I took video and posted it to Youtube, lest people not believe me.

The taillights, and most other systems, sprang on after 40 years.
The taillights, and most other systems, sprang on after 40 years. Rob Siegel

Now, as I described in a past article, when I beat on Lucas, I’m not just repeating hearsay. I have firsthand experience with Mr. Lucas’ legendary vintage British electrical products, due to a disastrous but fairly typical experience with a 1970 Triumph GT6+ I bought after high school and owned from 1976–78. The car was a rolling Lucas joke (that is, when it was capable of rolling). I was particularly fond of the wipers that quit working in the rain and the headlights that magically shut off at night. It was so bad that it cured me of British cars for 37 years, an inoculation that worked until I bought the Lotus in 2013. And now, here I was with a car that hadn’t had current coursing through its veins in 40 years, and most of the electricals worked. Keep in mind that this is not only a British Lucas-equipped car, but one with a fiberglass body, meaning the grounding wires have to be extra-long to reach the steel frame. How was this functionality even possible?

I posted the event to my Facebook page, and the responses were fascinating. One friend said that he had exactly the same thing happen with—go figure—a GT6 he’d recently bought as a barn-find car from the family of a man who’d passed away. The car hadn’t seen daylight in nearly 40 years. Like me, he dropped a battery in it and nearly every electrical system simply came up working. Another friend who has owned a bevy of Brits said that the contacts on Lucas-produced switches are poor, but if you keep them dry and use contact cleaner, they’re fine. A third offered that many, if not most, of the bad rap of Lucas electricals doesn’t come from the electrical components themselves, but from the ham-fisted attempts at jury-rigging around the problems—for example, wires hastily cut, spliced, twisted together, and wrapped with electrical tape, which is a recipe for poor electrical connections.

Although this is initially surprising, if you think about it, it all makes perfect sense and fits flawlessly with the revisionist history of ’60s and ’70s British cars we often read. I’ve seen multiple pieces where folks who own well-cared-for MGs and Jaguars wax rhapsodic about driving the cars to events on sunny Sundays, rhetorically asking, “Were they really all that bad?” The answer is: Yes, they were, but how a restored or well-sorted car behaves when you treat it as a pampered classic is completely different than how it reacts to being a daily driver forced to soldier on through rain, mud, sleet, and snow while being maintained on a shoestring budget—as most of them were when they were simply inexpensive used cars.

But to come full circle, let’s get back to the fact that one of the things on the Lotus that didn’t work was cranking the ignition switch to the start position.

When I took the drivetrain out of the car nearly six years ago, I was very careful to label every electrical connection with those little tied-string tags. The starter (or more specifically, the starter solenoid) has three connections. There’s the big one to the positive terminal of the battery. There’s the spade connector that comes from the ignition switch. And, as is sometimes the case on a vintage car, there’s another spade connector that is powered while the starter is being cranked. Often this is used to bypass a ballast resistor, giving the coil a full 12V while cranking. All of these were labeled, and all were put back exactly where I found them.

Of course, when you buy a dead car, particularly one that last ran in 1979, you can get into trouble by assuming that things were wired correctly and working flawlessly before you took them apart. Wiring issues often turn into achieving three levels of understanding. The first is, “How is it supposed to be wired?” The second is, “What on God’s Earth did someone do to this poor thing, and where can I find them, so I can beat them up?” The third is, “What do I need to do to fix it?”

The wiring diagrams for the Europa show the starter connection as straightforward as you’d expect it to be—one wire from the ignition switch to the solenoid. However, I read in a Lotus forum that some late Europas like mine have a “logic box” that include a seat belt interlock. I thought that must be it, but when I checked my car, it didn’t have this box. So I needed to trace the wiring and figure out where it went off the rails.

First, I checked the wire to the solenoid and verified that when the key was cracked to start, there was no voltage on it. Next, I crawled under the jacked-up car and traced the wire forward. To my surprise, it didn’t go into a wiring harness, but instead was one of two stand-alone wires that were stretched under the frame of the car. They went through a hole in the firewall behind the driver’s seat.

This wiring clearly wasn’t original.
This wiring clearly wasn’t original. Rob Siegel

So I pulled out the driver’s seat to continue tracing the wires and was stunned to find that they weren’t connected to anything. They were both just lying on the floor under the seat, although both had ring terminals on the ends, indicating that they clearly were once connected to something. Very odd.

At least on a fiberglass-bodied car, wires like this don’t ground out.
At least on a fiberglass-bodied car, wires like this don’t ground out. Rob Siegel

At that point, there was no choice but to examine the starter terminal on the back of the ignition switch and trace the wiring forward from there. Fortunately, the electrical part popped off the back of the keyed tumbler (the car would be trivially easy to steal), allowing me to see the terminals. The wiring diagram shows the accessories setting as “3,” ignition as “2,” and start as “1,” but those labels don’t exist on the switch itself. So I mapped it all out by rotating the switch to each position and using a voltmeter to see when each terminal had voltage. Below is a photo of the switch. By the time I was done, I’d figured out that the terminal without a wire on it was “1” for the starter.

Mystery solved. Bluetooth starter wiring doesn’t work very well.
Mystery solved. Bluetooth starter wiring doesn’t work very well. Rob Siegel

In other words, turning the key didn’t fire up the starter because not only wasn’t there anything connecting the ignition switch to the starter, there wasn’t anything connected to the starter terminal on the ignition switch at all. The nearest that I can guess is that, at some point, perhaps someone had installed a starter relay under the seat and the wire leading to it had been pulled out, but it’s just that—a guess.

With the starter connected, the next niggling electrical problem was that the tach didn’t work; it was stuck reading 6000. I noticed that there didn’t appear to be a separate wire from the negative side of the ignition coil feeding the tach, just the condenser wire to the distributor. The wiring diagram clearly showed an additional white wire from the coil to the tach, yet none was present. I thought perhaps that the tach had been jury-rigged using the other wire that ran under the seat, but it had 12 volts on it, so that couldn’t be it. To my surprise, after I cranked the engine for a bit, the tach, along with the other gauges, sprang to life. Regardless of what the wiring diagram showed, the tach was connected to the coil via a branch on the distributor wire that ran through the wiring harness.

Once I got the Lotus’ engine started (yes, it’s now running; I’ll write more about that next week), Lucas completed the hat trick. Initially the “ignition” light on the dash stayed on, indicating that the alternator wasn’t charging the battery. I verified this by connecting my voltmeter across the battery terminals and finding only battery voltage (12.6V), not charging voltage (closer to 14V). I checked for broken wires to the battery and indicator light and they were fine, indicating that the alternator itself was at fault. I began looking at replacement alternators, but as the car warmed up and the idle smoothed out, when I revved the engine, the ignition light went out, and the voltmeter showed 14V. Wow.

So, Mr. Lucas, wherever you are, I apologize, at least for the moment, for repeating the “Lucas vacuum cleaners—the only Lucas product that doesn’t suck” joke. Although you must admit that one is pretty damn funny.


Rob Siegel has been writing the column The Hack Mechanic™ for BMW CCA Roundel magazine for 30 years. His most recent book, Just Needs a Recharge: The Hack MechanicGuide to Vintage Air Conditioning, is available on Amazon (as are his previous books). You can also order personally inscribed copies here.

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    I had a 1974 MGB that was a victim of wiring patch jobs. Thankfully, electrical diagnosis is a strong suite for me.

    It took a month of picking away at it in my spare time, but I completely restored the harness back to factory and got everything working in the car as it should.

    My personal gripe with Lucas is the “many circuits, one fuse” philosophy, along with the possibility that rubber grommets never made it to the UK, and thus all wiring is doomed to get cut through at every metal crossing.

    I needed help getting off the floor. I was laughing so hard tears ran down my face. I told my wife I was not dying but flashing back to misspent youth and time with Mr. Lucas and his electronics.
    Thanks for a great read and good luck with the Europa. My personal hell was a 59 Bugeye Sprite.

    In around 50 years of being owned by British cars I’ve found the majority of issues are either grounds (earths in Britspeak) or corroded “bullet” connectors. As to the actual Lucas components I’ve had far worse luck with Botch (Bosch) items on my various German cars!

    Yah well…. I’ve been working on the cars for 50 years and without exception, the majority of issues I found were one of two things. Corrosion/arthritis from sitting for years or people who shouldn’t even be allowed to possess a straight blade screwdriver “working on” the electrical system. FWIW, the switches that worked the wipers and the headlights on that GT-6 were Clear Hooters, *NOT* Lucas. Those switches were awful.

    Oh, using the original kit cars (Lotus 7), and from a company that designed cars to disintegrate as they crossed the finish line, is hardly an index of the British car industry as a whole. And any time you make a fiberglass car, there is extra electrical paths to accomodate since there’s no such thing as a body ground. Lotuses (Loti?) and TVRs were notorious for grounding isues. One might be surprised to hear that there is a whole country that considers their home market cars to work just fine. The Brits were known for their back-alley, boutique, small batch car companies that cobbled cars together from existing parts. The various manufacturers shared many components.

    Your wiring under the seat was most likely for a “kill switch” as one of the few anti-theft devices available !

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