Electrical issues from corrosion?

FLABOTINUM

MEMBER
2006 FORD MUSTANG
4.8L
V8
2WD
AUTOMATIC
109,000 MILES

I have the vehicle listed above GY with 105,000 miles on it. For the past 6 years, after I hit 100,000, I got another car and only used this car from April to October (I'm on long island). I cover for the winter with a battery tender. However, 2 winters ago I had mice get in under the hood and they made a nest behind the radio. They chewed wires which caused the DVD changer to cycle on and off (even when I wasn't driving) causing the battery to drain repeatedly. This took a while to figure out. So, to avoid that, this winter I bought a car jacket tarp the encloses the entire car. Made the mistake of using that on an outside car. When I opened it up in the spring I had all kinds of corrosion. Some white stuff under the engine block and some electrical issues (key FOB not working and climate control blower totally unresponsive). My local mechanic thinks the corrosion on the engine block isn't a big issue and will come off when I drive in the rain. Unfortunately, the electrical issues were determined to be bad corrosion (blue colored) on the passenger side fuse panel and the surrounding wires. He even found some pools of water in that area. I've had issues with water leakage before and still some currently. I'm not sure if this corrosion is from that or storing it in the tarp. My mechanic said id need a new fuse panel but can't find any new ones from Ford (discontinued) or through his usual channels. That's the first issue I have that I could use help on. The second is, he says even if I got one the corrosion on the surrounding wires would still cause problems and have a cascade effect on the new fuse panel. Thats the second issue. Can the wiring and corrosion be addressed/replaced if I were to find a new fuse panel? I've put a lot of time and money into my car and it's important to me.

1 Reply

AL514

MECHANIC
4,698 POSTS

Hello, you can try to find a used fuse panel, if they are discontinued thats your best shot, as for corrosion, it sounds like you have a lot of it, Any main ground locations on the engine block, to the frame and body should all be take off and cleaned, If they are a braided ground strap then replace it. The green corrosion is the worst. I dont think relying on the rain to wash corrosion off is a good idea, using some electrical contact cleaner is good for corrosion in connectors, Ill post a picture of the best type to use. But really I would do one ground at a time. Ill post some further information on voltage drop testing in a minute.
This is the absolute best terminal cleaner for electronics you can get. WD40 makes one too that isnt to bad, but Deoxit D5 is really the best.
Another thing you can do with a basic multimeter set on 20VDC, if the engine runs at this point, is check for voltage drop first on the Ground side of the system. So from battery negative to the engine block, and battery negative to the frame. You should have less than 1volt, really the lower the better. Youre reading how much voltage is being lost between the meter leads. So if you read 12volts for example that means you have an open ground connection.
You can do the same on the positive side of the vehicles electrical system. So from battery positive to the Alternator positive post. but mostly on the ground side to begin with,
The problem with fuse panels, is once you notice some corrosion either in fuse or relay locations, most of the time the corrosion has gotten inside the fuse panel by then. This can cause circuits to short out, damaging modules, blowing fuses, and cause intermittent electrical issues that will really be difficult to figure out. Getting at least a used one is a good idea if things are as bad as they sound. Take pictures of fuse/relay locations and connectors before you start to unplug and replace things. Then you have a reference for when youre ready to put it back together. Ill post some wiring diagrams of the ground locations to check, so you have them if you run into issues when you get it started.
Rodents love to chew wires, they will eat them right up. They like the taste of the chemicals in the insulation. Usually in the spring this is a big issue with vehicles that have been stored over winter. Youre better off to put something around the vehicle to deter the rodents, then covering the entire vehicle like that. The sitting water puddles can do so much damage.
Diagrams 1 and 2 go together, top and bottom, and same for 3 and 4. These are the Grounds for the entire vehicle. Ill post the powers as well. And if you need anything specific, just ask.
The Power diagrams are 6,7- 8,9 -10,11 -12,13 top and bottom if you want to print them out.
Is the fuse panel youre looking to replace the interior one, on the driver side lower kick panel? This is a Smart Junction box, meaning it is integrated into the vehicles CAN Bus data network, and communicates with the Radio and Instrument Cluster, just something to be aware of. Most times when modules like this are replaced, they need to be programmed or have the data and VIN number from original module uploaded to the new module.

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Images (Click to make bigger)