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I am trying to repair a car wire that goes to an antenna (powering 'comfort access') that seems to have been chewed up by some animal / insect / rodent -- the original wire is a 20/22 gauge wire and the wire I used for the repair is a 18 gauge - cutting a small piece of the damaged 20/22 gauge wire out and replacing with the slightly larger 18 gauge -- the comfort access feature I was hoping to fix is still not working and I am still trying to trouble shoot the issue, is it possible that somehow not using the exact wire size could trip up the car system / antenna / sensors from working properly or is this not a likely culprit?

Thank you

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  • Can you post snapshots of this wire break (close-up and end connections)?
    – F Dryer
    Nov 26, 2023 at 15:07

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If this is a plain-vanilla 1-conductor wire that carries only power, the car won't care if you use a heavier gauge. The one time in a car that you should not use a heavier gauge is when the wire is used as a fusible link (a primitive kind of fuse) in an unfused circuit. Clearly, this is not a fusible link.

However, if this wire to the antenna is carrying a radio signal, you have entered the RF Voodoo Zone. Does the wire have an internal copper wire plus an outside shield of braided wire, twisted wire or some kind of foil? Here is one example: (stewmac.com)

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If this is what you repaired with plain wire, it won't work. The best repair is to find wire exactly the same as the damaged wire and replace the entire length from end to end. Any splice that you make in a wire that carries a radio signal will severely weaken the signal unless very special splicing techniques are used, beyond the scope of this Stack. RF voodoo, like I said.

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  • Hi there, nope, the wire that needed the repairing had an outside shield like the one in your photo and in it, two insulated wires each containing 5-6 tiny copper pieces -- the wire used for the repair, however, contained an insulated 18 gauge single copper wire - I used one of these and spliced with each of the two wires leading to the antenna Nov 25, 2023 at 19:03
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    @AnchovyLegend No, that won't work. The radio signal from the antenna stops at your splice and can not reach the receiver. The most certain repair is to get a replacement cable from the company that made your car. If not available, check electronics suppliers for the same cable. There will be a minimum order for this kind of cable such as 100 feet / 30 meters or similar.
    – MTA
    Nov 25, 2023 at 20:23
  • hi there, curious, why this repair wouldn't work and why would the radio signal from the antenna stop at the splice? I appreciate the help Nov 25, 2023 at 21:04
  • @AnchovyLegend The easiest way to understand this is that a splice in this antenna wire is bad juju due to the radio frequency voodoo that I mentioned before. Radio doesn't work like plain DC electricity. Need more? You are creating an impedance mismatch at the splice which reflects incoming radio frequencies back to the antenna and short circuits the transmission line from passing the small signal that remains. As to why, follow the first four linked pages that start here: antenna-theory.com/tutorial/txline/transmissionline.php
    – MTA
    Nov 25, 2023 at 22:42
  • Thank you so much - I will read the link you shared. I ordered the correct wire. When I use the correct gauge & wire type for the repair, is there a specific splice method that is recommended to ensure a successful repair aside from soldering? I was planning to use "Wire Butt Splice Connectors" thanks again for your help! I will post back once I attempt this repair with the correct wire Nov 25, 2023 at 23:50

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