Chewed harness repair resources

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bloc

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@Taco2Cruiser and other gurus.. what kind of wiring does toyota use? Particular ratings for under hood vs interior environments?

A squirrel decided to make a nest of my engine bay and I want to do as good a job with the repair as possible. I've figured out how to find connector part numbers in the FSM/EWD, and assume I'll be able to find terminals and repair leads.. but if I need to run new wires, what type?

@TeCKis300 do you know anything about resources on high quality crimp procedures and tools? Or anyone else?

My understanding is crimping is superior to soldering in high vibration environments, though I could be getting that confused.

Thanks

Btw the pups will be chicken food tomorrow, and I'm going scorched earth on the rest of the squirrels around here. I stress enough about rodents in the mountains.. will not stand for this in my driveway.

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Are you sure the squirrels weren't framed by mice? Dayam@#! So sorry to see that especially with how much you take pride in maintaining your truck.

Yes, crimping is superior in high vib environments. Solder can be done with proper strain relief of the wire immediately after it. Unfortunately I don't know what system Toyota uses. Perhaps someone else may know?

Do you know all the wires they got? Looks like they didn't get that ABS harness right near there as that one is critically tied in with a multitude of wires. The ground one there shouldn't be too bad to repair. The one near the airbox I'm not sure what it is either?
 
Are you sure the squirrels weren't framed by mice? Dayam@#! So sorry to see that especially with how much you take pride in maintaining your truck.

Yes, crimping is superior in high vib environments. Solder can be done with proper strain relief of the wire immediately after it. Unfortunately I don't know what system Toyota uses. Perhaps someone else may know?

Do you know all the wires they got? Looks like they didn't get that ABS harness right near there as that one is critically tied in with a multitude of wires. The ground one there shouldn't be too bad to repair. The one near the airbox I'm not sure what it is either?
They actually chewed these a week ago in preparation. I didn't know exactly what did it, but that mice in an urban environment seemed really odd. Also no bedding at that time. I crimped the wires just enough to get it good to go for the storm, and all the lights went away. It sat for 3 days from friday til today, when I go to put washer fluid in it, and see an adult squirrel sprint across the engine bay, and find two pups by the brake MC, and one down by the PS res.

The ground wires handle a major part of the ABS system, and wiper motor. PCS/ABS codes, wipers don't work. 2 small wires to that little black box. Interesting thing is in that area they chewed exactly the wires they did before, no more. Then the wires in the front right apparently have something to do with the front parking sensors. Six wires chewed clean through there, and they got the two or three that run the leveling motor in that headlamp.

I actually did some digging and toyota lists part numbers for their crimp sleeves and silicon tape in the repair section of the EWD. At this point my only issue is making sure any wire I get is rated for the same temps/chemicals.
 
For factory wiring, Toyota doesn’t exactly use anything that substantial as far as gauge or copper content. It’s not anything cheap though. That all said, I don’t integrate anything aftermarket into factory harness for reliability reasons, unless it is a requirement by the owner.

But when I need to fix burned up wires from customers who have tried to integrate their own electronics, I use like wiring from salvaged 200s. I have a few 200s harness that I take what is needed from. That way, it’s exactly the same, and with less time on them than what they go into.

Like Teck said, crimping is best for vibration resistance. What I like to do is use a bit of everything. I lay down a very little amount of solder, within a Delphi type crimp connection. Then I have a Toyota factory level of crimp, with a spec more of love. Then I heat shrink it all into a very tiny little package. So don’t think this is some bulky connection. It’s super thin and with the exception of the heat shrink, but you would not be able to tell there was any solder in there at all. Also, if I have to connect a lot of wires all in the same general area, I stagger the connections. That way, I can make it look more uniform in girth, instead of an obvious lump of connector mass.

Also, get a multimeter out and make sure everything is flowing good. Never hurts to make sure the finer things are still tidy.
 
For factory wiring, Toyota doesn’t exactly use anything that substantial as far as gauge or copper content. It’s not anything cheap though. That all said, I don’t integrate anything aftermarket into factory harness for reliability reasons, unless it is a requirement by the owner.

But when I need to fix burned up wires from customers who have tried to integrate their own electronics, I use like wiring from salvaged 200s. I have a few 200s harness that I take what is needed from. That way, it’s exactly the same, and with less time on them than what they go into.

Like Teck said, crimping is best for vibration resistance. What I like to do is use a bit of everything. I lay down a very little amount of solder, within a Delphi type crimp connection. Then I have a Toyota factory level of crimp, with a spec more of love. Then I heat shrink it all into a very tiny little package. So don’t think this is some bulky connection. It’s super thin and with the exception of the heat shrink, but you would not be able to tell there was any solder in there at all. Also, if I have to connect a lot of wires all in the same general area, I stagger the connections. That way, I can make it look more uniform in girth, instead of an obvious lump of connector mass.

Also, get a multimeter out and make sure everything is flowing good. Never hurts to make sure the finer things are still tidy.
Good stuff, thanks for the detail. Now to find chunks of a modern toyota harness to pull parts from...
 
Btw the pups will be chicken food tomorrow, and I'm going scorched earth on the rest of the squirrels around here. I stress enough about rodents in the mountains.. will not stand for this in my driveway.

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For post-crimping.
 
Damn they're cute aren't they;)

Automotive wiring is mostly cross linked polyolefin insulated. I can't tell how bad it is from the pictures, but I can almost always repair rodent damage without replacing factory connectors. It can be pretty intricate, but I've always been successful even times when the wire was chewed through as close as 1/4" from the terminal. I use non insulated butt connectors and heat shrink, preferably the adhesive lined variety. If you think you can repair it yourself, I'm happy to send you a care package of wire snips in either 22, 18, 16AWG GXL or TXL or larger AWG if needed along with heat shrink, non-insulated butt connectors or ring terminals all for the cost of shipping.

It probably sounds funny, but a cut/chewed ground can frequently cause more widespread problems than a single positive wire. But they're also the easiest to repair.
 
Damn they're cute aren't they;)

Automotive wiring is mostly cross linked polyolefin insulated. I can't tell how bad it is from the pictures, but I can almost always repair rodent damage without replacing factory connectors. It can be pretty intricate, but I've always been successful even times when the wire was chewed through as close as 1/4" from the terminal. I use non insulated butt connectors and heat shrink, preferably the adhesive lined variety. If you think you can repair it yourself, I'm happy to send you a care package of wire snips in either 22, 18, 16AWG GXL or TXL or larger AWG if needed along with heat shrink, non-insulated butt connectors or ring terminals all for the cost of shipping.

It probably sounds funny, but a cut/chewed ground can frequently cause more widespread problems than a single positive wire. But they're also the easiest to repair.
You sound knowledgeable in this space. What can we use to prevent critters from living in our engine bays aside from Patches, the garage cat.
 
You sound knowledgeable in this space. What can we use to prevent critters from living in our engine bays aside from Patches, the garage cat.
It’s definitely not always possible for security reasons but leaving the hood propped slightly open (12” or so ) has significantly reduced rodent damage on cars that sit for a few weeks or months. Supposedly they don’t feel secure with the hood open.
 
Chewed wires are a common issue in my area (mid-TN) and to my knowledge there are no real "preventative" measures you can take outside the vehicle, aside from Patches, as you say...lol . Some folks just have issues with them, and they don't seem to discriminate in rural vs metro areas. I live in a country-like setting next to a forest, and have had no mousey problems. Other ppl in town have 2 or 3 back-to-back episodes where rodents have caused wire damage.

Funny story. We had a Sienna come in with chewed wires to the Direct Injection system underneath the manifold. (2019 model IIRC). So we gave them a loaner Sienna while theirs was being repaired. When we got their Sienna fixed, we had to then repair the Sienna we lent them because the rodent had infiltrated the loaner vehicle and chewed the harness, almost in the same place.

I have found that the anti-mousey tape Honda puts out is great stuff. I have never had a repeat rodent-related failure after wrapping the repaired area in that stuff. Hope this helps!
 
It’s definitely not always possible for security reasons but leaving the hood propped slightly open (12” or so ) has significantly reduced rodent damage on cars that sit for a few weeks or months. Supposedly they don’t feel secure with the hood open.
What about opening it fully? My truck sits in my garage for weeks at a time on a battery tender. I could leave the hood open no problem.
 
Dryer sheets seemed to have worked well for me. Stuff them in the openings in the sheet metal around the perimeter of the engine bay. Mainly used for mice but I hear squirrels dislike the odor too. I also lay a few on the passengers floor. Seems to work , has on a few cars we have here .
 
Anyone have success using one of those electronic light/ultrasonic pest repellers?
 
We tried an ultrasonic rodent repeller and it was useless.
 
I haven’t decided what to do with the really thick ground wires bolted to the inner fender.. having trouble finding toyota quality wire so far. But I did decide to use standard toyota harness repair wires for much of what was damaged.

The female terminal for connectors that plug into things like the condenser on the driver side inner fender is 82998-12440
Comes with about 4” of wire on it and the rubber weather plug installed.

Then I did some research into harnesses for racing cars and found some common things in how toyota builds harnesses. I settled on brass open barrel splice connectors. The crimpers squeeze it together and the open ends turn back into the wire holding it very, very solidly. This is basically what toyota does for every crimped connection on our vehicles, and there are thousands. If it’s good enough for them, it’ll work for this. They are quite sensitive to sizing though, so it’s definitely not one size fits all.

Add some glue lined heat shrink tubing, done.

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I’ll update with more when I sort out the large ground wires.
 
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I just returned to Vermont from a trip out to Oregon, popped the hood and was greeted by a nice little nest, no pups though...

Where does the white stuffing-like material come from? I know the yellow is the sound deadening from the firewalll... I can't find any evidence of chewed wires or connectors, and I'm not having any electrical issues or lights on the dash.

I had to laugh because while out in Oregon, the house I was renting had a ground squirrel that took up residence in the gas grill. I wonder if he relocated to my truck out of spite...?

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I had rodent chewing issues too. Now I have a sticky trap permanently in place in the engine bay. When I trap a few I replace the trap.
 

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