Could the manufacturers not use wire insulation that is unpalatable to mice?

 

If I recall correctly in a large discussion in an automotive forum, the decision of automakers to switch from petroleum-based wiring insulation to plant-based insulation, it was both a cost reduction and a “green” environmental regulation.

Like all decisions made with good intentions but unexpected consequences, this plant-based insulation is appealing to rodents.
The end result? Consumers are left holding the expensive repair bills, which neither the manufacturer nor insurance companies will cover.
This is one of many examples in modern automobiles which, in the name of “greeness” have led to more and very expensive failures.

 

It's a corollary of Murphy's Law that Unintended Consequences tend towards the bad side. That's certainly true with the stupid things politicians do.

But in this case the unintended rodent problem led to innovation of wiring coatings that are highly undesirable to rodents. I may be wrong but I think they offer more protection than ever before.

 

could use armored or at least shielded cables, metal connectors etc. this of course would add weight and cost.

 

During the Covid crisis, one of my cars was a total loss after a rodent infestation. The insurance paid considerably more than I expected: 19K on a car I bought new for 28K 8 years earlier. The bump in used car prices at the time helped.

 

I left a file on my workbench, and it had one of those soft-touch handles. The handle is mainly made out of some hard type of plastic, with inserts of plasticised PVC. A rodent had chewed it, but only chewed the PVC insert.
It made me wonder if LSZH cables might be less interesting to rodents as PVC.
I have reels of cables, (PVC included) in my shed, and no rodent has never eaten the cable whilst it was on a reel.

 

Could the manufacturers not use wire insulation that is unpalatable to mice?

Not really. Manufacturers can add deterrents (like bitter coatings or soy-based insulation), but there’s no guarantee mice will still chew wires to keep their teeth worn down, even if it tastes bad. Plus, making insulation completely “mouse-proof” would raise cost, affect flexibility, or introduce safety/environmental issues.


For background on rodent chewing behavior:
https://en.wikipedia.org/wiki/Rodent?

 

Here in germany I have only heared about martens chewing cables. A remedy that helps quite good is putting a wire mesh with about 1 cm mesh size underneath the car. Martens don't like the mesh.

 

If I recall correctly in a large discussion in an automotive forum, the decision of automakers to switch from petroleum-based wiring insulation to plant-based insulation, it was both a cost reduction and a “green” environmental regulation.

Like all decisions made with good intentions but unexpected consequences, this plant-based insulation is appealing to rodents.
The end result? Consumers are left holding the expensive repair bills, which neither the manufacturer nor insurance companies will cover.
This is one of many examples in modern automobiles which, in the name of “greeness” have led to more and very expensive failures.

Rodents have been chewing wire insulation pretty much since insulated wires were invented.

I had a '89 Ford Probe that sat for a couple of months in an area that had quite a few field mice and when I went to start it a lot of the wiring had been chewed to the tune of over $2000.

Ask an exterminator or an auto mechanic that has been around for a long time and they will tell you that rodents chewing wire has been a long-standing problem.

Having said that, today's cars have smaller, tighter engine compartments that are more inviting to rodents and modern cars have a LOT more wiring, and more of that wiring is in tight bundles. So there's a lot more opportunity to chew on something and it's more likely to result in a wire-to-wire short. Plus, cars are a lot more sensitive to damaged wires than they used to be. Previously, a significant fraction of the wire in a car could be broken and not prevent the car from operating. Today, there's a lot of wires between components and systems that are critical to the car being able to even start or keep running.

 

Perhaps a high-power, varying frequency, ultrasonic pest repeller under the hood would keep the mice away.

 

I left a file on my workbench, and it had one of those soft-touch handles....

I have geckos that eat pieces off the soft rubber knobs on my DSO.

 

Rodents of some kind do attack wiring outside in my area, including coaxial cables running to the house. Shooting the creatures with an air gun works until more of them come along.
There is a trick with overhead wires, which is sections of plastic pipe slipped over tha cable befor installation. It serves as armor, and in addition, it makes it very difficult for the beasts to walk along the cable. It works well on those wires that run to garden lights, on the ground. I can use the plastic fittings without any glue, so that revisions are possible.
AND, certainly rodents seem to like engine compartment wiring in other peoples cars. I have not yet suffered that problem.