FWIW, both of those are in parallel. The 3 resistors in series are the same as the one resistor, but the resistors are in parallel with the bulb. If someone tried to put the bulb and resistor in series it would really not work.

4-bulb wiring harness is in parallel anyway.....

Quite a different design from the one's I have, plastic & folded pins trying too much to copy the 921 bulb. All of the ones I got are solid state, no plastics, just PCB's & solid contacts. Nothing to melt or break loose... not saying that it's going to make these work where those failed, that's mostly a matter of whether they got the electronics done correctly...

Currently a dead point.... All the other rear lights work, and the high brake assembly, with the Auxito red LED's installed, works in the LT, but put the assembly into the LS & nothing. I'm going to go pickup some standard 921 halogen's & see if maybe it's just the LED electronics that aren't working well with the LS???

Eliminated fuses as a possible culprit, checked under hood, and right side under dash, all fuses good. All other lights are working, even the tag lights, so looks like I've got to find some broken wiring, but how... everything is wrapped up tightly.

Also, just read that the ESC/traction control might also be tied in? Anyone know if this is true or not?

Tighten the 4 bolts in the under hood fuse box. They’re 7mm and you need to tighten them past clicking noises, the pins need to be pulled up tightly into the connection.
I check mine every oil change, just to be sure.

They do not tighten any further. I mean I could force them, but I'm already at 25 inch pounds (+/- 1.37%) of torque on each bolt. Since I cannot seem to find info on the bolts, I have to go by what I know, 7mm socket is normally a m4 / m4.2 bolt m4.2 typical torque range is 22 to 31 inch pounds. Just looking at the threads visually, I would guess they're at least m5, but don't want to go by a guess....

FIXED!!!! I must have spent between 1 & 2 hours trying to find the 3rd brake relay, the way it was worded in one post, I had started to think that it was only in the HHR Panel....

Tonight, I finally found a youtube short that showed exactly where the 3rd brake light relay was located. Opened the hood & sure enough, there it was. Grabbed the known good relay out of the LT, put it in the LS, & the 3rd brake light is now working!!!!

I'll check tomorrow to see if cruise control is working. I'm starting with the halogen bulbs first just to verify if it works or not before switching to the LED's.

Awesome, you found the relay, it is kinda hidden away from the fuse box.
let us know about your bulbs

Cruise Control now works, Auxito LED's do not work with Cruise Control, but it appears the LasFit LED's DO work. I say "appears" because I only had 2 of them to try, pulled two of the four Auxito bulbs, & exchanged them for two LasFit bulbs, and cruise control works under that configuration.

Ugh... the Airbag dash light is back, so no more cruise control till that's fixed :( Unfortunately, the dealer did not show part # for the "connector" they want to replace for $483...

At least Google gives me some starting points.... all done after disconnecting battery of course.

• Check Under-Seat Connectors: Locate the yellow electrical harnesses under the driver and passenger seats. Disconnect them, ensure they are clean, and reconnect them securely.
• Passenger Seat Sensor: The HHR often has issues with the Occupant Classification System (OCS) sensor in the passenger seat, which can be triggered by heavy items or faulty weight sensors.
• Front Impact Sensors: Inspect the front impact sensors located behind the front bumper for corrosion or damage, especially if you live in a snowy area, as they are prone to failure from moisture.
• Code Scanning: Use an OBD-II scanner capable of reading SRS (Supplemental Restraint System) codes to pinpoint the exact fault. my current scanner does not support this :( Might try to get the Innova SD39 or SDS43
• Battery Reset: Disconnecting the car battery for 15-30 minutes may reset the system if the fault was temporary. Tried it already, it still came up after 1hr disconnected.