The Rear & Trunk lights are a bit limited, especially on the Interstates, only showing Turn signals and don't show Parking or Brake action. I couldn't find a "4 to 2" converter, so... I designed to share.
BTW, this is a pretty simple project and easy to do even if you have only a little experience soldering.
This design converts the OEM 4 wires to 2 wires (not inc ground).
This means, you can changeout the 1057 single filament bulb in the rear with an 1157 (dual filament) receptacle. This adapter will properly feed the 1157 bulbs and show Turns, Park, and Brake actions!!
(Suggestion: Replace the rear light assemblies with 2 of the Front Turn Signal Light Assemblies.)
OEM ADAPTERLeft \
Right --> Left High/Left Low (1057/1157)
Brake --> Right High/Right Low (1057/1157)
Tail /
BOM:
-3 Relays TE RT424012
-3 Diodes 1N4148
-4 Diodes 1N5400
-1 Plastic Box 2.4 x 1.4 x 1"
SOURCES:Plastic Box:
https://www.amazon.com/gp/product/B07D23VBNT/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1PCB available from OshPark.comhttps://oshpark.com/shared_projects/k7OZj5gZSuggested Assembly Instructions:VERIFY ORIENTATION BEFORE SOLDERING1. Add to the BOTTOM the three 1N4148 Diodes. Snip excess from the top to make space for the relays.
2. Add to the TOP the 3 Relays
3. Add to the TOP the four 1N5400 Diodes.
4. Connect wires, as appropriate for your setup. (I added 6pin Connectors to make it easier)
Simulation:This site allows basic simulation. Only problem is nothing is labelled and you have to manually click the switches to simulate the turn signal going on/off.
https://everycircuit.com/circuit/5609503619547136Jumper Function: (personal preference)
OFF = When BRAKE & TURN are both active will flash between HIGH/OFF
ON = When BRAKE & TURN are both active will flash between HIGH/LOW