05 Sonata, 2.7, auto trans

Prior to this issue, I only replaced the battery, the old battery had 1 dead cell so it would go dead overnight beyond that which would start.

I replaced the battery in parking lot in snowstorm with limited tools. So I was unable to remove the battery hold down (bolt was a little rusty) and had to yank the old battery out so it could be returned for a core. The new battery spent 3 days no hold down and I had no issues. I changed the oil, checked filters, tires, put hold down back on, and next day catastrophic nonsense followed.

My wife went to use the wipers, they wiped twice, then total shut down (car continued to run), no wipers, no power to the HVAC controls as well as the blower, the headlights went off (not the parking lights), no power to the sunroof, no power to the starter giving a no crank when I went to restart it once she got home.

I pulled and tested every fuse with a meter, tested the relays, swapped relays out and moved some to other positions, replaced the ignition switch as it seemed to turn over when I rotated the key in start (a complete fluke I found later), and now, well now, I have power when ignition is in the On position, I have parking lights, power locks, radio. However, I have no crank on starter, no lights on HVAC, no blower, no power to sunroof, no headlights, no wipers and no clue where to even look anymore. I found on this forum to check the negative battery cable, which I did and seemed logical as I had no battery tie down for 3 days, cleaned the connections, dielectric grease, seemed to work for half dozen starts, then back to square 1. The car is littered with relays etc, the relay under the pass side kick panel will click erratically at times causing heat to go on and off and intermittent start and power to the balance, I have not yet replaced it as I have no car currently, (my car is waiting for a transmission swap, yet another tragedy of not being able to find the correct replacement!) and well, the parts store is a brisk 5 mile walk in wretched winter conditions!

I plan to replace the negative battery cable entirely today, with a new ground point on both the body and the engine, as well as replace the engine to body ground. It seems to be more of a ground issue then anything, but I am unsure, and well Google, seems to find countless people with any one of these issues, with each seeming to have different fixes that I have tried most outside replacing countless parts! I also plan to replace the relay under the kick panel also, as it acts erratic and when it does kick on, things seem to work.

Otherwise, it really feels as though I have a bad ground somewhere, that kicks sometimes, and not others. I have used dielectric grease on everything I have fiddled with thus far, as well as clean any terminals etc. I may replace the positive terminal also, it has been cleaned etc, yet it is the original and perhaps corrosion has gotten to parts of it causing a weak positive.

Is their a circuit breaker or relay that controls or regulates all the power going to components with high draw?

I am at a loss, any suggestions would be great as I have tried countless over the past few days, spending hours outside in negative temperatures getting nowhere yet. I have not looked at the starter yet, and apparently there is a lead to it that fails sometimes, seems I have to pretty much remove it to access it which I cannot do at home unfortunately.

 

Believe me , I know very well what it is like trying to work out in the cold and trying to do some intricate work checking voltage readings.
If you can, The relay that is clicking intermittently, try to confirm it is getting full voltage and has a good ground. As you are probably aware a poor connection will read OK UNTIL you put a load on it. If it is of any help , most of the time electrical problems are the result of poor connections.
Starting right from the battery, make sure every connection in the train is clean and good. Also as you know by this time , just looking at them does nothing , they need to be removed cleaned and reinstalled. Simple things like a ground wire connecting the sheet metal to the engine can be overlooked and many times that prevents other circuits that rely on that ground from working correctly.
Another thing, you need to confirm proper voltage is coming out of the ign sw to the fuse panel and items it supplies power to. If you have a copy of the owner's manual, in there you should find what fuses/relays are in the vehicle and what they control. It will save you loads of time and trouble. Not knowing if anything was done while the holdown was off , when you finish going over everything, you might consider what we call a soft reset. That is, removing the neg cable from the battery and holding it against the positive cable for a few minutes. Many times this will allow gremlins to exit. Keep in mind you will loose radio stations and some memory functions and will need to staret the vehicle and don't touch the accelerator pedal, allow it to idle and relearn some info, also as you drive it , improvements will take place Sorry for the long winded conversation, but hopefully it will take care of the problem.

 

I did the reset already twice, nothing changed. (I used same method to reset my Jeep when I did work to the fuel system)

Also after cleaning the electrical components I did fiddle with, I used dielectric grease on reassembly.

I cannot test voltage to relay as it is not getting power currently.

I replaced negative battery cable as well as grounds, still at square 1, after I warm up I will try to test voltage to the ignition switch itself when in the run position and see what I find.

 

Don't forget to check the fuses at the fuse panel(s) for good connections when the key is on supplying power to ign controlled items. Could have good power to fuse , but not after fuse.
In the owner's manual, it should supply the info as to which relay controls what and you might go from there. Without a wiring diagram the only thing you can do is trace the wire color at the relay in question and see if that color is present at the fuse panel. I realize this is the hard way to do it , but sometimes we have no choice. Here again , if you know what relay controls what , then in the owner's manual you will know where that particular fuse is located and make sure full power is coming out of there ..
You can always confirm the relay coil of the relay you suspect is good., unless you already swapped it with another of the same size/type. There should be a constant voltage supply at one of the relay pins. When the relay is energized that power is now sent to what evidently is intermittent.
If the relay has nos, 30, 87, 85 &86, 30 is the hot supply 85 is the ground , usually supplied by the computer and 86 is the hot supply for the relay coil. When the relay gets energized , it transfers power from term 30 to term 87. Sometimes we jump 30 and 87 to prove that part of the circuit is what gives us the result we want. You might consider confirming that 86 and 85 are doing what they are supposed to do and either supplying power or ground to the respective terminals and see if the relay is working at all.

 

Most of the things that have no power require the key turned to on position (except radio)
And since, you say intermittent, I would suspect a wiring issue. Must HVAC blower set to high so you can hear it.
Then do visual inspection. Moving wires bundles as necessary. When it comes back on then on right track.

Tough to find. If that is the problem.
Good luck

 

For a 2006 Hyundai Sonata does anyone know what this wire is coming down out of the left side of the battery from the collection of wire connections going to spark plugs and other electrical points. It basically goes down and connects to a round connection at the bottom most part of the engine block. Obviously it has been damaged and can be contributing to starting problems but trying to figure out what it specifically is. Thanks for any help!