MR2 Roadster Owners Club

The Workshop => Audio / Security / Electrical => Topic started by: archieatkins on February 28, 2010, 20:26

Title: hmm flat battery might be coming on
Post by: archieatkins on February 28, 2010, 20:26
Hey All!

So i was driving home tonight in the dark and thought i had my window slightly open so i went to put the window up and as i pressed the button my headlights and dash lights went dim, tried this a few times and they went dim everytime and at varying speeds.

never noticed this before and dont really need anything else to happen to the car at the moment.

Anyone else experienced this? Is it time to change my battery or something?
Title: Re: hmm flat battery might be coming on
Post by: DannyN on February 28, 2010, 22:02
I only spotted this recently in the wife's clio and asked the clever bods here and its just cos your loading the battery up by trying to get the window motor to wind up when its already at full extension.  absolutely normal and nothing to worry about
Title: Re: hmm flat battery might be coming on
Post by: Mike68 on February 28, 2010, 22:18
If it was your battery you'd have noticed starting problems during the cold weather we've had. If it was an alternator problem the battery light would show on the dash to say the battery is being used.
As already said, this is normal as long as they don't go really dim.
Title: Re: hmm flat battery might be coming on
Post by: cclarke99 on February 28, 2010, 23:26
Agree with the other posts that it's probably not a problem. If you want to check the alternator then measure the battery voltage at about 2000rpm with all large electrical loads (e.g. headlamps, rear window) switched off - it should be 13.2 to 14.0. To check the battery, run the engine for long enough to be sure it's fully charged, switch off, turn on all electrical accessories for 60seconds, turn off and measure voltage, should be 12.5 to 12.9V
Title: Re: hmm flat battery might be coming on
Post by: mrzwei on March 1, 2010, 16:43
Agree with all of the above. When you turn the ignition on and you only get a clicking sound then you have to jump it, charge it or change it. Two weeks without use and mine is fucked so I jump it.
Title: Re: hmm flat battery might be coming on
Post by: archieatkins on March 1, 2010, 19:03
Cool Thanks for the posts.

I use my motor every day so i am sure i will find out when it just doesnt want to start. To be fair it has probably happened ever sinse i bought it and i just never noticed.  s:) :) s:)

i am observant like that.