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The circuit that controls headlights, interior lights, gauges, power door locks, etc. went poof the other day only to come back on its own the next day while I'm driving (yes, I first checked the fuse ACC and baffled when I saw it was OK only to be more confused when things went back to normal the next day while driving after a few potholes --of regular size, nothing major ). I am assuming rattling prevented the power the reach the light switch by either somewhat partially dislocating a connector or loosening something inside the switch and want to control the lighting switch itself and its connections.
I am looking for the location and the picture (so I can recognize it when I see it ) of the light switch shown at middle of the diagram below ; where exactly is it located? Almost everything on that attached diagram stopped working; since in the middle of it, there is a rectangle called "light switch", I am assuming that it is a SINGLE part that I should investigate: power is fed to it by point A, on the left upper corner of the light switch rectangle via a circuit breaker inside that switch; I assume this is where things went wrong since it is the ONLY power input point to the whole light switch system aside from the ACC fuse which is fine. However, tail, backup and stop lights and turn signals were working which means Tail fuse was working therefore the circuitry in the light switch, meaning the one in the middle of the rectangle, was working AND also the power was coming to ACC fuse, too, since they are fed by the same line from the battery in the fuse box; those brown lines (at either side of the convenience center and radio receiver) are to tail, stop and backup lights and turn signals. Since my power locks, dome lights, headlights, power outside mirrors, horn, hatch release were not working, all this points to ACC fuse controlled circuitry which was fine, as I said. Then, I must assume that the light switch was receiving power via that point A (on the left upper corner of the rectangle). The only remaining deduction is that either the circuitry on the right side of the light switch rectangle must be faulty, or the ACC fuse intermittently stopped receiving power due to bad connection at the juncture. I am very confused at this point! The 2053 page Service Manual mentions LH Pod as its location only once and without further detail.
Thanks in advance for the help.
I guess not that: I further elaborated by editing the original post, but going with the symptoms, everything on that attached diagram stopped working. Since in the middle of it there is a rectangle called "light switch", I am assuming that is a SINGLE part that I should investigate. Power is fed to it by point A, on the left upper corner of the light switch rectangle via a circuit breaker; I assume this is where things went wrong since it is the ONLY power input point to the whole system aside from the ACC fuse which is fine.
The **** has been pulled out / removed,...... but that's the ---- "rectangle called "light switch", --- that your looking for. Pretty sure I can even see all 7 terminals as specified by the diagram that you posted in that picture.
.........The circuit that controls headlights, interior lights, gauges, power door locks, etc. went poof the other day ............
I can promise you this ;
The power that runs your power door locks most certainly does NOT come from your headlight switch , so if the power door locks along with the headlights and other things are behaving oddly , It's not the headlight switch's fault . You fault lies in whatever feeds ALL of those different things power , and you should be checking things like fusible links to see where power is , and isn't , following the power distribution path right from the big wire on the starter to where the bad connection lies .
My ignorance Great! Now please help me out with this, please:
This is a list of what stopped working: Gauge, dome, interior, rear view mirror, under hood lights AND headlights; power locks, hatch release and possibly horn (but I am not sure as the plastic on the SIR unit gets very hard to push during the winter).
My tail, stop, backup, license plate and turn signal lights were working.
As far as I can "read" the diagram, a faulty light switch or the loose connection to its point A (red wire) would cause all those symptoms, correct?
For right now , forget about your lightswitch , it doesn't distribute power to anything but your lights , and a lot more than just your lights aren't working .
Now , the commonality to all those things is that fusible link , it's that fusible link that must be your first check . A quick Google search will produce all kinds of videos about checking/changing fusible links , start there and chances are very good that you may find your problem . Just remember , although they can fail from age , a "blown" fusible link blew for a reason , if a replacement also blows there will be a short circuit somewhere in one of the circuits fed by that link (your hitting of a bump and crazy power stuff happening suggests there very well could be wires shorting to ground somewhere , a nightmare troubleshooting exercise for all but the most experienced in automotive electrical work)
Just to clarify: if there were to be a short and blew the fusible link, the system shouldn't have come back by itself, correct? Also, I did look into those power distribution schematics, but cannot see any fusible link line that feeds the headlights AND the ACC fuse (which is the fuse that leads to all the shutdown circuitry) for the life of me OTHER THAN fusible link A (as shown in the schematics), BUT IF that one was the problem, my tail fuse fed circuitry must have also stopped working, but my stop, tail and backup lights were all working fine. This is really confusing
Yes, indeed, everything came back and working now, and I'm pulling what's left of my hair since And yes, that bad connection that SHOULD explain both of the seemingly independent symptoms eludes me from looking at the schematics (now I included all three at my original post. I guess the only thing I can do is to wait for an encore performance AND THEN check things out; what a mess! But, at the end of the day, one should be theoretically be able to pinpoint the problem given the symptoms against the schematics, I just can't
I think your schematic shows g5 at c100 for being the fusible link power.
have you checked that for power ?
your wires could have melted and caused a open and remade a connection . Just a thought you should start at c100
Yes, exactly, that is the common connection, BUT ALL my tail (fuse) circuitry was working during the problem which definitely means fusible link A and C100 and g5 must be working; otherwise tail and stop lights will be gone, too. Besides, everything "miraculously" came back the next day and now everything is working, but that's beside the point: I still should be able to theoretically pinpoint the problem by using the schematics against the symptoms, but it just doesn't make sense
S231 or g200 check out ok ? Or have you even tested ?
Right now, everything works so there is no point; I need to wait until the problem occurs again. I was going to run the tests, but the circuits came back all of a sudden. Besides, Defogger, turn signals and radio was working which are all grounded from g200, so if it was loose, they shouldn't. Regardless, I will try to track it properly IF I get this again, which I should, normally and soon.
Right now, everything works so there is no point; I need to wait until the problem occurs again. I was going to run the tests, but the circuits came back all of a sudden. Besides, Defogger, turn signals and radio was working which are all grounded from g200, so if it was loose, they shouldn't. Regardless, I will try to track it properly IF I get this again, which I should, normally and soon.
Even if everything is working again for now, I would still take a look at a power distribution schematic for your specific thirdgen, and take a look at the wiring harness to see if you can see anything that might have been the cause of this problem like a corroded ground connection, or melted/ loose wire, in an attempt to try to nip this problem in the bud before it rears its ugly head again.
Besides, everything "miraculously" came back the next day and now everything is working,
Sure sounds like a bad fusible link,... or a melted terminal at the back of the fusebox.
if there were to be a short and blew the fusible link, the system shouldn't have come back by itself, correct?
Yes, and no. In the case of a HARD short,... sure. But; what "sucks" about fusible links is that they usually fail due to age/rot & not normally due to a HARD short to ground. They almost always look fine and don't normally show a physical defect when they fail. It's far more common for them to cause intermittent problems rather than a full 'all or nothing' failure.
Still, what bugs me is the headlights: if fusible A did this, how come all the tail fuse circuitry was working since it is also fed through fusible A. In any case, I need to first and foremost wait for the problem to occur and then properly check the failed vs. working components to troubleshoot it on the schematics, and only then go to the wires; otherwise, it is madness, madness, I tell ya!
01-21-2020, 01:29 PM
). I am assuming rattling prevented the power the reach the light switch by either somewhat partially dislocating a connector or loosening something inside the switch and want to control the lighting switch itself and its connections.
I can promise you this ; 
And it's still not your headlight switch .......
