Adam wrote:
Sajiyev,
I have a 2011 Ford Ranger Super Cab 4×4 4.0 Sport with 52,000 miles. I bought it in 2014 with 7000 miles on it, so I know its history pretty well. Recently, the power mirrors stopped working. I checked the fuses and the 5 amp fuse was blown. I replaced the fuse and the power mirrors started working again. However, when I started the truck I immediately heard the 5 amp fuse blow again.
I looked it up and based on the wiring diagrams on the internet it looked like the power mirror was the only thing on the circuit so I knew I had to take this with a grain of salt. I decided to unplug the power mirror switch and replace the fuse. I think the switch might be the cause. When I got back in the truck (the fuse box is on the passenger side footwell) I swear I heard it explode again when I opened the driver’s side door.
Do you have any suggestions on how I can track this down? I googled a few videos but most found severe shorts like this due to body damage or the wiring harness being compromised from corrosion or something really crazy.
I saw a YouTube video on the South Main Auto channel where an Altima had a fuse that kept blowing after replacing the throttle body. A new fuse box was brought to him to replace the ECM. He decided to follow the wires down and traced one of the wires in the fairing. Apparently, instead of clamping the wiring harness, the factory attached it to the wiper armature and ended up cutting one of the wires that controls the throttle body.
Any ideas other than something crazy like this?
Thank you,
Adam
PS I do have an official 2011 Ford Ranger shop manual and wiring diagram that I ordered off eBay last night.
Sajiyev Answer:
No, the wiring issues you see on YouTube are not a “crazy” thing. A short to ground fault may be your problem, but before we get into that, let me suggest that wiring issues are very common in modern cars.
There are many points of failure in a modern supply chain, so you must be prepared for any scenario. The factory may forget to push the retainer in all the way, install the clips, etc., which can end up causing the wires to scrape against other objects. Or maybe the harness supplier forgot to add said clip or retainer in a specific location? Sometimes, car manufacturers even “forget” to design it into the wiring harness!
That’s why I’m glad you purchased the shop manual and wiring diagram because you absolutely need them. Since this might one day apply to my 2011 Ford Ranger, I dug into the wiring diagram to see what should be done. At least in theory.
Page 124-1 suggests that you need to check the BR-RD wire (brown with red stripe) in the fuse box to see if there is a problem along its entire length. The first connector to check for damage (C527) is the one on the switch that you disconnected, so this may not be your problem. But check the condition of the BR-RD wires at the plug and inspect the wiring harness for signs of damage.
The second connection for the BR-RD wire is at C210, inside the dash, above the pedal assembly. The BR-RD wire at C210 is the first pin in the harness. (Check pages 150-26 of the manual to see what I see). Check and disconnect C210 and test again. This is also a good time, and it’s worth noting that there are better tools for testing for shorts to ground than some new fuses.
This video will help you do the rest, but shorts to ground typically occur when accident damage repairs, aftermarket parts, or just general sloppy work results in a wire getting tangled up where it doesn’t belong. Good luck, although this should be easy in such a simple vehicle.
bonus!Piston slaps nugget of wisdom
YouTube is a great motivator and educator, but no one is going to pull out a wiring diagram to show you the wire colors and where you need to go. I mean no one. Who pays attention to detail in YouTube videos?
Well, except for this idiot who couldn’t even hold his phone while making the video. How amateurish!
Bottom line: Use Facebook groups, YouTube videos, and even automotive forums to get advice to point you in the right direction. But when it’s your turn to troubleshoot, getting the factory shop manual and especially the wiring diagram is a must for any do-it-yourselfer. They’re not cheap, but over the past 30 to 40 years, most vehicles have paid for themselves after a few repairs.
Do you have a question you’d like answered on Piston Slap?Send your questions to pistonrapp@hagerty.com—Please provide us with as much detail as possible so we can help! Remember, this is a weekly column, so if you need an expedited response, please let me know in your email.
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