Dead Battery or something worse?

[tandlehill]

Hope someone can help with this.

Just recently my Mk 1 VRS has been playing up when starting, seems like a flat bettery but then it will eventually start. :thumbdwn:

When I get in the car in the morning and turn the key all seems fine, turn over and I hear either a very poor turnover followed by clicking, the interior light "pulsing" and the rear passenger and front passenger doors locking.

Once the car starts the battery light goes out and it runs fine; now my thinking at first was that it was a dud battery (blown cell?), but that wouldn't explain why on some occasions I have this performance and then at other times it starts without a problem.

I did notice that the other night when I was going out of the side door to my house the interior light was on as if I'd unlocked it, I did have the keys in my hand but definitely hadn't pressed the fob, then it mysteriously locked itself again. I suppose this could be the timing when it auto locks itself if the door hasn't been opened but it doesn't explain how it unlocked itself first??!!:eek:

I've had a read on the forum and can't really decide if it's the battery, a loose earth or faulty microswitch in the door?? :confused:

Any ideas or advice please?? Thanks!

[vRS G60]

May well be the battery. It is getting quite cold at night now and the drop in temperature will affect the cold cranking ability of the battery. If it is on its way out then it could well show the syptoms you describe.

[DeeBe]

Maybe the starter motor becoming lazy?

[tandlehill]

If the starter motor was getting lazy wouldn't I struggle more with the start up rather than have some crazy electrics too?:confused:

Interestingly the car died completely on Saturday, tried to jump with cables and whilst it turned over it wouldn't start up, almost as if there was absolutely nothing in the battery at all even with the boost from a slave battery .

Now I am going to buy a new battery today but wondered if anybody thought it might be something other than the obvious?? I'll be purchasing a heavy duty battery this time, particularly as it's getting into winter.

Any ideas or advice greatly appreciated!!

[Bowders1]

Why don't you go to your local garage or dealership to get battery tested.

Even Tyre places do this now for free. This is a quick test to check the charge of the battery prior to starting and the running charge passing it through it when load is applied from switching various things on. At least you know what the condition of the battery is.

Garages and Dealership should not charge for this also. It is so quick to do.

If you don't know when your battery was changed or suspect it to be over 4-5 years old I would replace it anyway.

Slow starter motors can also cause strange starting issues and cause that clicking sound(solenoid being triggered on starter motor) This will cause dash lights to go on and off as the current is passing through the ignition system.

[vrs180]

Just a word of caution on battery testing.

Batteries should be fully charged prior to "high rate discharge" testing, otherwise the result is meaningless.

[tsr2]

I did notice that the other night when I was going out of the side door to my house the interior light was on as if I'd unlocked it, I did have the keys in my hand but definitely hadn't pressed the fob, then it mysteriously locked itself again. I suppose this could be the timing when it auto locks itself if the door hasn't been opened but it doesn't explain how it unlocked itself first??!!:eek:

That's fairly common in my experience. I find that the buttons on the fob are very sensitive and will respond to a little nudge from another key on the ring or something else in your pocket as you take them out. It's often pretty hard to tell what triggered the unlocking, but I'm confident that something will have nudged the unlock button.

[VWD]

Just another take on the situation .Trying to put this non technical ,but any poor connection in the feed from the battery to the starter or on the return earth path would drop volts .( Bloke called OHMS discovered that current times resistance =volts , and that would reduce the voltage getting to your starter)

Now the intermittant bit could be due to a bad cell or a bad connection .I'd have the battery checked out at somewhere like crapfit ( sorry Quickfit),unless you've got a meter -then you can look for volts drops ( as in between battery and starter ,and between chassis and battery negative).And when at it -check charge rate ( from memory iddling I'd be looking at about 13.5v, at revs up to 14.4-again from memory)

Seem to remember that the solenoid should not drop more than 0.5 volts - in olden days it was possible to take it apart ( used to do it on my old maxi,every September) and clean up the contacts -doubt if that's possible now .

[Roker]

The clicking you hear is the voltage protection relay, If the volts in the battery drops too far the relay cuts the ECU etc off, and if the voltage rises again it clicks in, causing a cycling. Why mess around and risk more damage if the battery is poor? Mine was droping out at about 7.5 volts after I accidently left the ignition on for a few hours.