AndyT1

A few days ago, as I got into my 2010 RX 350 and started it up, I got check engine light, AWS warning and and exclamation mark, with the car running rough at idle.
Luckily I had a chance to bring it to my mechanic and he initially thought it was going to be spark plug related. However, I got a call a few hours later saying it looks like the main wiring harness was chewed up by rodents...
The car is in great condition and only has about 72,000 miles and roughly 9 years old. I was actually planning on another 5 years from it.
The mechanic inspected the car and there are a number of wires that have been chewed off/have chewing marks. He is planning on repairing only those places instead of replacing the main wiring harness. His argument is taking the engine out to replace and putting everything back in will not match the quality of factory job. Should I insist he replace the main wiring harness - this will be under an insurance claim - or just take the car to a dealer (probably Toyota, as they are closest and I have been using them for most of the work).

Nad1370

mcomer

Wiring that is "Eco-Friendly" or biodegradable is apparently very tasty!
Honda now has a tape to wrap wiring with to dissuade the hungry varmints.

AndyT1

I am already going through my insurance company - so I will be out only $500. My question / concern : is fixing an existing harness just as good as putting in a replacement one?

RickC5

The answer to your question is simple: Repairing something (virtually ANYTHING) will never be as good as replacing the "broken" thing with an original part, and could actually lead to more problems/issues down the road, depending on the completeness of the mechanic's diagnosis and the quality of the repair. Since you have already claimed this with your insurance, I recommend replacing the entire harness.

Clutchless

Has your insurance said they will pay to replace the harness? Confirm that is the coverage situation before abandoning his repair efforts.

salimshah

It depends upon who is doing the repair. If done right it can be as good as the original, but it requires skill and dedication. One has to add new wires and solder them as well as shrink tube them. The skill is required to stagger joints and weave the wires.

The things that are not being discussed and partially allude to by NAD are
1. How to prevent the rodents from coming back
2. How do you determine if all the places that were chewed have been identified.
3. I would also check the cabin filter as that is a typically where they make their nest.

Salim

mandyfig

Meanwhile are you addressing the root cause? Need to stop the rodents entry to your garage (assuming it is garaged).

Non

I want to confirm what was said before.
I've been working with wires for more than 20 years, and the wire harness can be repaired. If done right it will be as good as factory, or it can be even better On top of that, it's not very hard to do a good job repairing wires, but it takes a little bit of patience.
The problem is you can't tell if the technician did a good job or a poor job just by looking.

AndyT1

Thank you all. I ended up moving the car to a Lexus dealer. However, it seems they may also consider repair although I may not sure if I should insist on replacement. The service advisor said it may take up to two weeks if the harness needs to be replaced. It's snow storm weather today, so they will have more details tomorrow.

tus

I would tend to agree with your mechanic on this one. Remember, everything that has to come off to replace a harness will have to be put back on correctly.

The other major problem is with how the harness is installed when the thing is on the factory line. It's usually laid in when there are very few parts attached so trying to get the old one out and new one in would require either taking it all apart, splicing in to the impossible to get at but undamaged portions, or getting creative on how you route certain things.

tus

I get a chuckle ever time someone tries to blame the biodegradable plastic for rodent damage I doubt anyone who claims this has ever tasted the stuff.

I've actually used it for 3d printing, including the soy based stuff that the Japanese imports use, and having bitten into the stuff since my filament cutter was out of reach or lost somewhere, I can tell you it is just as unappealing in taste as the hydrocarbon based stuff. It doesn't taste like soy sauce.

Comes down to rodents like to chew on wires for some reason, have done it in cars and boats for decades before the new insulation was out, and would still be doing it if it never existed.

coolsaber

wiring harness damage replacement depends on how bad it is. If its a simple small section that can be rewired they`ll take that method. if its so badly damaged, that you cant make heads or tails of stuff, in different sections and areas, where modules have basically have an intermittent failure they will opt of a new harness ($$$$). It all depends on the extent of damage and of course whose footing the bill. Insurance like an owner will want to go with the low $$$ option. However seeing how the OP moved the vehicle to an dealership, you might have some leverage on the owners side since they work on standardized per hour rates, and usually arent so quick to fold unlike indys. Plus the repair will be as close to OE spec as possible and backed by the dealership. Any improper installation, and you know they have to make it right.

AndyT1

The dealership ended up doing what my mechanic suggested - repair, as the cost was the same as my deductible, I cancelled the insurance claim. I was a bit surprised, as I thought they would want to replace the harness, but the service adviser said their techs recommended repair and that I shouldn't see any issues.

coolsaber

Lexus backed at least. Make sure you drive the vehicle around in varying environments to check to see that fix is good.