Have you tried to disconnect the heated switches to see if the interior lights come on normal again? Sounds like something might be pulling down your voltage. How did you confirm your dimmer is not defective? Hard to see the schematics but I would definitely look at the junction blocks.
Illumination Circuit Woes
Greetings folks.
I have a 2016 LE Rav4 that I really enjoy. Back in 2019 I decided to install aftermarket seat heaters for the cold German winters. Many thanks to AndSpenRob with his fantastic post (2012 RAV4 aftermarket heated seat installation (lot of...) helping me accomplish this. I differed in where I wired the switchs up though.
Power: Left & Right Accessory outlets (cigarette lighters) power wires
On: Left Acessory outlet power wire & Unused traction lock harness power wire
Ground: Left & Right Accessory outlets (cigarette lighters) ground wires
Night Light: Seat Heater switches (G26/G27), + illumination wires
The problem is that sometime after completing the mod (unsure of how long) I noticed the some of my interorir lights either no longer illuminated or were significantly dimmed. I have checked the dimmer and confirmed this wasn't the problem.
Lights that have been affected include: Cruise Control Switch, Steering Pad Switches (weak, but on), Combination Switch (Eco/Sport mode), Telltale Light (weak, but on), all three AC control switches (the center LED on the power circuit unaffected), and the shifter illumination light. Everything on the radio/nav head is perfectly fine.
I tested the bulbs in the AC switches and everything is working fine there. I also took some measurements on voltage/amperage which I can provide if helpful. I attached the wiring diagram below, but frankly the power and ground paths
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running across multiple junction blocks are very confusing. I am at a loss on what I can do next for troubleshooting. I am thinking to test the Junction Connectors on the path of the lights that are out, but would welcome any inputs or thoughts.
I have a 2016 LE Rav4 that I really enjoy. Back in 2019 I decided to install aftermarket seat heaters for the cold German winters. Many thanks to AndSpenRob with his fantastic post (2012 RAV4 aftermarket heated seat installation (lot of...) helping me accomplish this. I differed in where I wired the switchs up though.
Power: Left & Right Accessory outlets (cigarette lighters) power wires
On: Left Acessory outlet power wire & Unused traction lock harness power wire
Ground: Left & Right Accessory outlets (cigarette lighters) ground wires
Night Light: Seat Heater switches (G26/G27), + illumination wires
The problem is that sometime after completing the mod (unsure of how long) I noticed the some of my interorir lights either no longer illuminated or were significantly dimmed. I have checked the dimmer and confirmed this wasn't the problem.
Lights that have been affected include: Cruise Control Switch, Steering Pad Switches (weak, but on), Combination Switch (Eco/Sport mode), Telltale Light (weak, but on), all three AC control switches (the center LED on the power circuit unaffected), and the shifter illumination light. Everything on the radio/nav head is perfectly fine.
I tested the bulbs in the AC switches and everything is working fine there. I also took some measurements on voltage/amperage which I can provide if helpful. I attached the wiring diagram below, but frankly the power and ground paths
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Thank you for your questions and engagement. So I have tried without the heater switches connected and it doesn't affect the lights at all. I have even removed the heater switch illumination wire from the illumination circuit and it doesn't resolve the issue. This leads me to believe permament damage may have been done but I can't say for sure. The heater switches are wired into the 12V power outlets which are a different circuit than the illumination so I would think they can't affect each other.
One big question I have is what the voltage across the switches should be in a normal scenario. There was 11.4V across the fuse which I would expect, but only 2.5-2.6V (.003-.005A) across the illumination terminals at the switches. That makes me think a voltage drop is the culprit. The problem is that I don't have a solid understanding of the circuit because it is so complicated with J/Bs. I can't even say for sure where the various parts of the circuit go to ground. I will repost the circuit as a full file for legibility.
As for the dimmer, I think it's good because it still dims and brightens all the functional lights without issue, and I can see the change in resistance over the A/C illumination wires with my multimeter.
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