friendlyx3

Background: recently bought a 94 es300 and have since been changing all fluids, brake service, tire rotation, etc, and have also been working on a p1300 diag code.
Unrelated info aside, if anyone can give me any info about this weird wiring setup I would be really appreciative considering I don't know where to begin reversing all this, unless it's recommended to leave it be. Thank You for reading and/or replying if you have any information

HomerJay

Could be a remote start bypass switch.
Is the key fob OE or aftermarket?

friendlyx3

It's just a single OE key. Also there's two switches -- one's under the dash and the other on the panel to the left. Sorry if the image isn't clear.

HomerJay

OE remote entry key? If yes, trying pressing "lock" three times and see if it cranks/starts
Are you able to ask the seller?
Did you try switching off to see what happens?

friendlyx3

It is a remote entry key yes however, no it does not start the car with 3 or more button presses. Switching both switches off changes nothing. I found a box tucked away that seems to be involved. The following two photos indicate a lone black wire coming from a wiring harness(tied into another wire) in the engine bay that once penetrates the firewall goes straight to that switch on the left panel. Does this all sound like a remote start to you? Maybe without the remote?
The seller is a family friend and it's doubtful she would know because she's in her 50s, and not only was it her deceased aunts car but she didn't mention it. I can ask when I see her again.
Tyvm for the quick replies.

Arsenii

Hello,

Did you try flipping them? What changes when you do?

Not sure about others, but I am really not a fan of aftermarket systems, especially the ones that were implemented so poorly. My 2000 Lexus ES300 came with enough of those, the first thing I did the moment I got the car is ruthlessly tear all of them out and away from the car, returning everything to stock. The problem is not the fact that you don't know what they do, it is the fact that they may cause a lot of grief in the future, for example if the previous owner cut into the engine control system and done a poor job at it, some wire can come loose and result in a ton of intermittent issues that are really hard to pin down, even for a professional.

To me those look like a half-hearted attempt at the alarm system, something like the one shown in the video below. The biggest advocate of this theory is the fact that you are missing the Fuel Pump relay, with some weird wiring stuck in its place. This is really not a way to protect a car from any kind of attempt to steal it, since something like that is extremely easy to trace, I just need to check power on all the critical components, like coils and fuel pump; in short, an average guy who knows at least something about cars will defeat it in less than a minute.


Trace all the non-factory wiring, see where it is going and what it connects to, if any of the factory wiring is cut and the switch is spliced in, cut the switch out and use heat shrink butt splices to connect the factory wiring back up, if you have any doubts, update this thread with detailed explanation on the switch in question, like from where to where it goes, and what it does when switched.

Hope this helps and best of luck!