Switched Rear Light Wiring Kit | Upfitter Interface Harness

Switched Rear Light Wiring Kit | Upfitter Interface Harness

Marsoni

M251S

$109.00

Get it in 3 business days with 1 day shipping. Friday, May 29

Switched Rear Light Wiring Kit | Upfitter Interface HarnessWant to control your Slimline Reverse Light Kit or Rear Bumper Lighting kit from a switch as well? This is the wiring kit you need! HOW IT WORKS This wiring harness plugs directly in line between our 7 Pin Reverse Light Harness and your LED lights. The other end of is connected to a switched relay (sold separately) in your engine bay. The harness is more than wires. It contains a smart circuit board that automatically detects the source of power so

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Exchange/Return Notes

We offer a 30-day return/exchange service after receiving.
Final sale items are not eligible for returns or exchanges.
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Definitely better than the old plugs that probably had 80k miles on them. The one star off is because I had a misfire after installing. Not sure if I damaged the plug or what, but a reinstall didn't fix the misfire. In my genius, I rushed to try to gap it and ended up breaking the iridium tip. Put the old plug into cylinder 3 (where the misfire was) and it was fine. Gonna have to get a new single tomorrow at my local shop, but a bit frustrating to get a misfire after install.

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Reviewed in the United States on April 27, 2026

Verified Purchase

Britincali

Draper, US

★★★★★ 5

Upgrade from OEM

After seeing a quite ludicrous $403 quote to change 4 spark plugs in a Mazda3 I decided to show my son how easy it is. These were an upgrade from OEM parts. They were gapped perfectly for the car. They took 20mins to fit and work fine.

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Reviewed in the United States on February 11, 2026

Verified Purchase

ANDRES FIGUEROA

Belleville, US

★★★★★ 5

Very good

The best quality. Runs like new again.

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Reviewed in the United States on March 12, 2026

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Ale

Battle Creek, US

★★★★★ 1

garbage spark plugs

misfired after 30 minutes of driving cylinder 4 misfire code, left me stranded on the highway with baby in car. “(9621)” at the end of description is a lie, was not compatible with my vehicle even with compatibility test.

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Reviewed in the United States on May 17, 2026