Worlds weirdest electrical issue

Maybe not the weirdest, but I have no idea where to start.

Recently I started to hear a crackle in my left front speaker. I have upgraded speakers and an amp, for full disclosure, but I put it in several years ago, all has been fine with it. One day I play with the volume control and the right speaker goes out. I pull off the door panel and find the cables are completely disconnected. Weird, but ok, I put them back on and the right speaker comes back on, but the left front goes out...wtf? I remove the left door panel and everything looks ok, jiggling wires does nothing. I remove the seat where the amp is to jiggle wires and swap left and right... so no matter which speaker I plug into the right side only the right speaker works, weird, but ok, maybe an issue with the amp, then suddenly the right blinker comes on, I'm on the floor in the back, no where near it. I turn off the ignition and blinker is still on, also only a right when I tried to select left with the signal arm.

First off, someone please assure me these two are unrelated, but...where do I even begin to try and figure this out? I disconnected the battery cable to shut this thing down...

 

Disconnect the amp and see what happens.

 

Thanks for the nudge. Shouldnt have fried my brain by trying to fix multiple things on the same day. The blinker thing seems to have fixed itself, but still the same speaker issue. Im guessing its an amp problem...

 

Don't guess. Get a Digital Multi Meter, and start testing.

The first culprit is going to be the speakers. Test them for resistance. Most speakers are around 2-8 ohms.

You can also use an AA battery connected across the speaker wire at the amp going to the speaker. If the speaker pops when you tough the leads to the battery, it and the wire are good.

If you're only using the DMM, check the resistance level of the speaker with no wires connected.

Then connect the wires to each other, and on the opposite side, connect the DMM to each individual wire. You should see something near 0 ohms.

Disconnect the wires touching each other, and test with the meter again. You should see something along the lines of infinite ohms--dashes, 'inf' or similar on the display.

Now leave the wires disconnected, and touch one DMM lead to a good vehicle ground point, and one to either wire-- it needs to read open or infinite ohms. Any resistance here means the wire is damaged. Now check the other wire the same way.

If all that is good, last thing we can check is the amp output and input. Set the DMM to AC input(around 20v if it's an option), and connect to the output of the amp. With music playing, you should see fluctuating voltage on the display. If not, do the same test on the input RCA. You'll likely see a fluctuating voltage close to 1-4v.

 

Electrical gremlins are the worst! (- I am not the best at auto electrics either!)

My first car was a FIAT. This was a 'real' Fiat from a long time ago. It was a great drive when it worked! - But Fiats were known for baffling electrics. (worse than the 'prince of darkness' brand LUCAS from old British cars! - That says a LOT!)

- At one point, if I pressed the car horn button on the steering wheel, I'd get a wipe (windshield wipers would activate).

I could never figure that out...
It fixed itself after a few days.

 

Fiats are not a good comparison for electrical issues. The wires them selves must be extra shitty. But I learned manual in an old fiat.
Had an old Audi in which the whole taillight corroded together, instead of a bright orange blinker, it was dull and slow, brake, reverse, blinker, and parking light that flashed.

 

If you swapped BOTH left & right speaker leads at the amp's output (left speaker leads connected to right amp output and vice-versa) and still only the right speaker worked, I think the amp (and everything ahead of it) can be ruled out as the culprit since the right speaker worked with being connected to either channel... It's more likely your wiring or the left speaker itself.

Agreed, a small flashlight battery is a good way to test things by listening for the *pop* sound it makes.

 

I use a 9 volt transistor sometimes. I used to have this tester years ago that you would connect alligator clips and press a button angle a tone if speaker was good

 

How old is your battery? Are the terminals corroded?

 

Replaced the battery about 2 weeks ago, but that wouldn't cause only a single speaker to go out...

 

Welp, it's not the speakers or the amp. I've pulled the head unit and now I'm just going to have to see if there is an issue from the the amp back to it. If the wiring checks out .This is exactly what I was hoping it wasn't as that will be the most expensive thing to replace...