Harrison Ford has an extensive collection of planes, motorcycles, and automobiles, but one of his favorite vehicles comes with its fair share of problems. The Indiana Jones star owns a 1993 Mercedes SL R129, which was designed to fail in a pretty major way.
Mercedes is a pretty forward-thinking company, and despite its love of performance-focused engines, it has had a bit of an eco-slant; it is always looking for ways to save the planet. This has led to the occasional bad decision, the worst of which arguably happened in the early to mid 1990s. The German manufacturer, along with several other European car companies of the time, decided to fit biodegradable wiring harnesses to most of its vehicles.
The soy-based harnesses were meant to reduce the amount of plastic waste ending up in landfills by simply decaying into nothing over time. They did this a bit too well, especially when exposed to the conditions you tend to find in the engine bay of a performance vehicle.
Constant heating and cooling, moisture, and vibrations tend to break the harnesses down a little faster than Mercedes originally intended. Which means owners have spent the last few decades chasing electrical gremlins, and ultimately performing pretty complex wiring jobs on their vintage German luxury cars.
The good news is, every one of these wiring harnesses is almost guaranteed to have rotted out and required replacement by now. So one of the biggest issues in automotive history will have resolved itself over time as owners bite the bullet and fix Mercedes’ mistake.
This has almost certainly happened in Ford’s case, as he’s still clinging on to his SL R129 (according to GQ, anyway). But it remains something you should definitely check for if you’re buying a German luxury vehicle (especially a Mercedes) from the 1990s. Mercedes used biodegradable harnesses between 1991 and 1996 specifically.
Ask for paperwork showing the job has been performed, or just pop the hood, squeeze a few cables, and check if they turn to dust in your hands.
Harrison Ford’s Mercedes may have had some other problems
Despite its wiring harness issues, the 1993 Mercedes SL R129 that Harrison Ford drives is not a bad car. It looks exceptionally good, with its square front and drop top screaming out “I had a lot of cash in the early 90s.” It came with a choice of straight-six, V8, or V12 engine, and no matter what you chose you were getting something pretty bullet proof. Especially for the time.
But there have been other problems noted with the SL R129. While the engine itself was solid, the M119 V8 version of the SL R129 did have problems with its distributor cap and rotors. They were prone to water ingress, which would then cause severe misfires. The plastic oil delivery tubes tasked with getting lubricant to the camshaft tappets could also crack, starving the lifters of oil and leading to failure. The straight-six engine (M104) tended to have a higher than normal head gasket failure rate.
Water could also get into the cabin through the top seals and window seals of the vehicle, which were prone to degradation. This would then lead to window fogging, or even pool under the front seats and short out the roof’s control module in extreme cases. Said roof is raised and lowered by a series of hydraulic cylinders, which fail over time.
This isn’t a problem with Mercedes in particular though, anyone who’s dealt with older vehicles knows that kind of cylinder is prone to failure, whether it be used to retract a sunroof, prop up a trunk lid, or form the basis of a vehicle’s suspension. With the latter also being an issue in the SL R129. Its adaptive damping system will leak over time, leading to an expensive replacement.
Aside from a couple of engine gremlins, these issues are more in the “it’s a vintage luxury car, what do you expect?” category than anything else and shouldn’t detract from the fact that the 1993 Mercedes SL R129 is a fantastic vehicle. Plus, it hasn’t had as many recalls as your average Ford, and it’s definitely better than the Austin Healey 3000 that Han Solo is also known to drive, anyway.
