I second this. I've had an alternator killed due to a bad earth terminal.Originally Posted by Turbo_Steve
Thanks guys, I am goin to redo th terminals as I had changed them when I bought the car and fitted a bigger battery. After investigating yesterday the cable isn't so good where it sits in the new clamp. I've got a gold plated one here that was waiting for an ICE install so I'll fit that and add some extra earthing to the engine bay.
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From the sound of things, you have something loose, which all the extra big earths in the world aren't going to fix.
I'd suggest you need to sit down with the wiring diagram from any 8G and establish which stuff is common that is failing.
Steve,
We actually stood outside the car yestrday with the ignition set to ACC, so no ignition, and the only thing active on was the stereo. Even then it randomly reset itself without us touching a single thing and nothing at all moving in the car.
I'm going to rip out the stereo and check behind it as a first action. Last night was shooping then the Quiz nightso there was nothing done to fault find
Hmm.....interesting. I wonder if you've got a short in the loom somewhere....
If it all works okay with the stereo removed, I'd look at the speaker wiring, I reckon.
I suppose the other possibility is that it's simply wired in wrong......dumping audio current into the system earth or similar.
Does it all still misbehave when the stereo is off?
Steve, I thought very much the same and tried driving around without the stereo switched on.....still happened. The stereo isn't very old and there wasn't an issue with it for the first 3-4 months I've owned it. The wiring to it is via a proper autoleads converter and any possible shorts were prevented with electrical tape. I'll still recheck there purely for the fact we all know how sharp the edges of the metal back there are and it's possible something has been damaged over time.
I'm also going to check around the ECUs as that has seen a large number of additional connections (soldered I might add) since I got the car, although nothing really in the time period the fault has been present.
My electrical issues should probably be in a separate thread but I'll add the current results here for now.
I have replaced the -ve battery clamp with a gold plated one and ensured it is well connected to both wire and battery. This has improved the flickering of my lights when pressing the brake etc and I thought had fixed the other issues but it seems it hasn't.
I stripped everything out of the centre console and re-did the earht for the HU. Unfortunately there's nothing to tell me if there's issues with the radio disconnected so I tidied up a few of the cables and put it all back in.
Initially it all seemed OK and both headlights came on first time and the car idled slightly smoother. The stereo didn't reset but on a quick test drive the ABS/TCS lights still came on. Returning home the stereo reset again and I found that with the key to ACC pressing the brake whilst the stereo is on will cause it to reset 4 out of 5 times. This happens less once the engine is running and can also be instigated by switiching the interior light on or off, flashing the headlamps or turning on or off the wipers.
There is definitely something very odd causing all of this and I'm sure it's still an earth issue. I get 12V engine off and 13.4V engine on so the alternator seems OK and both are stable over a period of 5 minutes.
The other thing I came across is that I can't get my OBDII cable to trigger the flashy dash any more but that may be because I've disconnected pin 4.
I stil have no additional boost control, as I haven't had a chance to test the solenoid I don't know if it's mech or elec till tomorrow.
What I would suggest is running a separate 12v feed to the HU, and making sure that the constant 12v wire isn't hooked up to the accessory wire.
That way at least you know that the power draw of the stereo isn't coming from the dash loom.
The above is good advice.
Also, try sticking a volt meter across the headunit power & earth...see what voltage the headunit is seeing when you press the brake.
Stupid question, but will your Headunit run with the ignition switched off (some do, some don't). IF it will, try powering it on and seeing if the problem with the brake persists.
Thing is, the headunit should be earthed to the chassis by the black cable AND from the aerial sheild when it's plugged in.
To get it to reset, you must either be taking one of the 12v feeds to 0v (it would be nice to know which one, switched or perm...hence the voltmeter)
Or it must be taking the earth to more than 0v (which is pretty unlikely if we're talking about the chassis!).
If you're certain about the earth fault, then try measuring voltage between the battery -ve terminal, and various chassis earths. Whilst replicating the fault. If you see voltage, even 1v, you've found your bad earth.
Also, see if there is a loose bolt grounding the fuse box... I can't confirm on our cars, but on another one I worked on I couldn't work out why the dash wasn't working, nor the fuel pump. Turns out I didn't tighten the bolt in the fuse box... which was coincidentally the ground for it.
The HU is wired in so that the memory line is permanently live and the actual unit only works in the ACC or ON positions but I can swap them round. The thing is this still happens if I turn the HU off, so it's only enough voltage to display a clock.
The battery is only two years old but it did die completely at th start of last year. Is it possible that the battery is duff and this is causing the issue? My only thought was that this shouldn't affect it when the engine is running as there's a healthy supply.
I'll contort myself into the footwell tonight and hopefully make up some earth lines.
Any progress on the brake shudder?
I have (and always have had) the same problem..
Might be worth looking at the ignition switch and connectors to all the loom under the shroud.
nah, no point in swapping them. I was only asking in case your Headunit allowed you press the power button with the ignition off, and start working.
As this seems to be relating to the brake pedal, perhaps it's worth having a look at the wiring around the pedal.....
As a point of interest, it may also be worth disconnecting the brake light switch and seeing if the problem persists.
Sydo, no, nothing much on that at all. It doesn't seem as bad at the moment but I've been concentrating on the dodgy electrics first as they are taking out the ABS/TCS which may subsequently affect any brake tests.
Steve, I'm going to be under there tonight I think and will be covering everything with a fine tooth comb. I'm not sure the brake pedal will necessarily be directly relevant as the ABS/TCS normally comes on only whilst accelerating/crusing, I've never noticed it happen when braking. I'm almost positive (pardon the pun) that this is related to loading of a poor earth or the battery. If it wasn't for the fact the car starts as soon as you turn the key I would have said battery/live terminal issues.
Thanks for all your ideas folks, I'm not ruling anything out yet. I appreciate it's difficult to diagnose form the keyboard but it all helps as I have nobody here to work through it with me. There will definitely be a round on me at the next event I get to!
Adding this more for info than anything.
Travelling home for luch with the facia of the HU removed the ABS lights still ended up appearing. Was driving over a bumpy surface but I think it's just coincidence.
Travelling back to work and the stereo and climate control were both off, same thing again. In addition I have noticed that at both times the car was about to shift into the next gear at around 3000RPM
I think your centre console is going to have to come out....TCU, ECU, Stereo wiring all lead to here.
OK, looks like I've managed to track down the cause of my flashy dash....and the reason I have no boost. The stupidly thin wire that goes to the boost solenoid had somehow managed to get sliced through by the strut brace and was shorting out onto it as I picked up speed. Unfortunately repairing the wire means I can send 12V down it to trigger the solenoid but not when the E-01 is connected. I can only assume that the output on the E-01 is blown which is going to be yet another expensive, if even possible repair.
UPDATE: Well not only does my EBC appear to be dead but the ABS/TCS lights came back on again just after I filled up!
We're now working out how much it will cost to put the car back to standard and sell off the upgrade parts. I'll then work out if it's work out more viable to get rid or repair. It's simply gone too far for me now and I'm struggling to do most of the work with a bad back and a lack of assistance.
Have you pulled the ABS/TCL codes?
I suspect that a dying battery could cause the issues, I know that a dodgy earth terminal on my car made the ABS and TCL lights flash up when braking. Try swapping it for a known good one and see what happens.
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