Hiya, I just had to jump start my 560SEC battery.
Started fine after being connected for 5 mins.
Took her for a drive and the temp gauge is flicking from 80 to 120 every second, also the fuel gauge might be acting up as it seems to be moving slightly. The oil pressure gauge is sitting on 2.5/3 normally it sits at 3 always.
I just installed a car stereo which seems to be working OK.
I'm hoping it's a low voltage issue, I have the battery on a conditioner overnight.
Has it been doing this ever since you installed the stereo?
If you have enough power to start the car and your alternator is working you shouldn't have any low voltage issues while driving.
Here in the states, we don't typically jump start the battery; we jump start the car. If you were doing the latter, it could still have a low voltage condition once you remove the jumpers, but, if they weren't connected when you started the car then my second statement should apply.
Yeah, this is the first time I have turned it on since the install, but the battery was also dead. I'll report in tomorrow morning when I start it on full charge. It's possible I shifted a wire somewhere while installing. I went through the grommet behind the glovebox, then behind the glovebox and down behind the centre console. It's pretty tight when I push the head unit in, but I'm not sure if any wiring for the gauges runs through there anyway.
I just had another look at the stereo install, and noticed that the HU is constantly powered...
Its obviously wired wrong, here are some details of how it's wired currently:
RED / ACC - "To the +12 V power terminal which is
energized when the ignition switch is set to
the accessory position" - currently this is attached to a red cable, which should be providing 12v constant, am I right in thinking this should be wired to the black 'Car' wire instead - from the bundled wiring loom - for 'ignition' This explains why it is always on obviously.
BLUE/WHITE / REM OUT - "To the power antenna (aerial) control lead or
the power supply lead of the antenna (aerial)
booster" - I have this connected to the subwoofer's power on trigger. Seems to be fine, the amp/sub turns on.
ORANGE/WHITE SRIPED / ILLUMINATION - "To a car’s illumination signal" - what is the illumination signal? Currently this orange white wire is connected to the Car's orange wire. I wonder if I need this wire connected at all?
The main power cable runs to a fuse near the battery then to the battery +
The ground runs to a loop fastened under a bolt on the side of the bonnet. It's tight, but is that a good grounding point?
Pic of the grounding cable/location and a pic of the cable loom wrapped insulated black shroud with a plastic connector about 3 inches further back.
I'm not sure why the two black wires converge in that loom, but I'll try connecting that black fork to the head unit / accessory.
Also, I will seal the ground and yellow/grey/blue/yellow-green wires up.
I don't believe any of the beckers were illuminated beyond the LCD screen, and even then it wasn't bright enough to warrant needing to be dimmed at night (when you turn your lights on), so I have my dimmer wire (orange/white) disconnected.
You car's orange wire may in fact be the brown ground wire. It's been years since I did my stereo install, so I don't even recall an orange wire.
ETA: It's also not uncommon to see many of the black wires (12V) coming together in other circuits of the car; my lower gauges in my 16V, for example, have multiple black wires coming together to keep the string of 12V power going from one switch, to another. Essentially daisy chaining from switch to switch.
Thanks VaiFanatic,
When I get home I'll try replacing the constant 12v on the ACC to the black wire.
I noticed that the brown wire (ground?) is exposed, and could have been touching something behind the head unit when its all pushed in. Probably not good.
Well, many headunits still require a constant 12V to power the internal clock and often times save your settings (though I believe newer units have means to save your settings, at the very minimum).
I have my black/yellow/green wires (those are what I have) connected to the red wire of the units wiring harness, that should power the unit when the key is in position 1 for Accessories. Your yellow wire from the unit's harness should be your constant 12V, direct connection to the battery. I can't recall what color that wire was that it connected to, I may need to pull the headunit out to take a look.
Look back at some grainy photos I took, I do have the same orange wire, but I left it disconnected and wrapped it up. When I swapped in my updated double din, I had wired it up to the harness, only to discover that turning my lights on threw the backup camera screen on the headunit!! Orange/White on most new units is meant to be wired into the reverse light circuit for the backup camera. All this information just came back to me looking through these old photos.
As an aside, I had issues from corroded battery main cables reducing voltage with several cars. With starting issues I always check those first.
I remember getting stranded, and Coca Cola on my Caddy's batteries neg strap ate through the corrosion and got me going again..
Vai, my head unit has a dedicated 12v and ground directly to the battery, as it uses much more power than usual, it's a 'true' 4 X 50W system.
So as far as the extra wiring to the head unit, I think all it needs is a 'signal' level input from the accessory. It should get all the power it needs from the high gauge cable it has already.
Green - I wired it myself last week, took out an old head unit and put the new one in, plus AMP/SUB.
Do you guys think the grounding location is good? Under that bolt you can see is bare metal (not painted) so I feel like it should work.
I'm guessing a diode in alternator is fried. Next time it's running, connect a meter to alternator and put it on AC setting to see if you're getting AC voltage. It would also explain why your battery was dead and flickering of instruments indicates a bad diode as well.
Thanks Nutz, Do you think it could go bad as a result of doing the stereo install, or just a coincidence?
The batt might have gone dead from the improper wiring of the head unit, constantly on, even with the faceplate detached, the amp in the sub might have been on the whole time, as it's trigger ON cable might have been active.
In addition, one could have insufficient alternator brushes left at this point > insufficient battery charge >> etc.
Two screws later. it could have a replacement installed… In my experience, with MY 560SEC, the Bosch branded ones have way stronger brush springs than say a KAELER for example.. The KAELER brushes were toast at 70 - 80,000 miles meaning I had to call AAA to get going again…
Thanks MBL,
My SEC has 220KM on it now and I don't know if the alternator has been changed yet. I am yet to get the service history print-out. Any tips on visually identifying if the bush springs are worn?
Forget about the alternator for now and get the stereo wired up correctly. The trigger wire must be on the accessory switch, otherwise, as you surmise, it will draw current all the time. This accounts for the dead battery. Nothing at this point indicates a problem with the alternator.
The illumination wire goes to the dash lighting circuit to dim the panel when you dim the dash lights.
After charging the battery for a solid day and night (stereo 12v disconnected) , I turned over the car this morning and the gauges stuck fast to their old positions. I left it running for a while, and occasionally the gauges would flicker, just a little and randomly.. not as much as previously. When I caught the gauges flickering, I gave it some gas and they went straight back to solid, and when the engine dropped to low rev's the flickered a tiny bit.
I need to give a little history on the car though, After initial start when the revs drop to low idle there is a mild to moderate squealing sound.. a constant tone, like a rotating part/belt at constant speed. It goes on and off for say a minute, then fades out. After the car is hot and running, it doesn't re-appear that day.
Anyway, this sound was MUCH shorter this morning, just thought I would mention that, as I'm guessing it might be the alternator dying now. I don't have a volt meter on hand at the mo to test her out.
I will get a recording of the startup tomorrow morning, I'm sure you guys will pick the prob from the sound.
Great! Do you guys know if the alternator in the W126 is unique to this model?
I might try to find a local one, or I could possibly buy a repair kit and do it myself.
The regulator and brushes are a separate piece, replaceable in situ. I'm sure it is covered in another thread somewhere. First, though, get the accessory belt off the alternator and give it a spin by hand. If it doesn't turn easily and smoothly, don't bother messing with trying to fix it; replace it instead.
While you're at it, check the condition of the belt and the tensioner mechanism. Even the best alternator won't charge if the drive belt isn't properly tensioned.
I'm thinking about getting one of these:
Bosch - AL129X
fits the same mounting point's and increased amp's. I read that others have used them well.
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