Does Custer 7-Way Round to 7-Way Blade Adapter Have Signal Converter in It

Updated 09/29/2025 | Published 09/09/2025

Products Featured in This Question

Custer Trailer Connector Adapter - 7-Way Round to 7-Way Blade

(24)

$81.76

Pollak Replacement 7-Pole, RV-Style Trailer Connector Socket - Vehicle End

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$14.85

4' Pigtail Wiring Harness for Pollak Replacement 7-Pole RV Socket

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$24.55

Roadmaster Brite-Lite 3-to-2 Tail Light Converter for Towed Vehicles

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$58.90

Question:

A 7 round on a semi truck has the brake lamps going thru the red wire stop cirucuit. On a rv plug the brake lamps go thru the turn signal circuits. Will this adapt the stop lamps correctly?

asked by: Shawn S

Expert Reply:

Hey Shawn, this is a great question but no the Custer 7-way round to 7-way blade adapter does not have a converter in it so that the separate signal circuits are combined. Basically this adapter is designed to just convert the styles of 7-way but not actually go from the semi truck style to RV style of wiring. To convert the signals you would need an converter like the part # RM-732 which you could splice into this adapter if you wanted.

Sometimes in situations like this you can wire in a second 7-way blade connector on the tow vehicle and then wire the converter to it. So you'd need the # RM-732 as well as a 7-way socket like the part # PK11893 and harness part # PK11998 to do that.

expert reply by: Jameson C

Jameson C.

9/29/2025

Hey Shawn, did you have a chance to try using the converter and additional 7-way socket to adapt the stop lamps correctly? I'm curious to know how it worked out for you, as it could help others facing a similar wiring challenge.