Brake light and battery light staying on!!

[tommytoneism]

Hi all,

           Please help!   Alternator belt been squeaking for a while, plus I took the battery off the other day to clean my air filter behind and my MAF. Did 70 plus miles all good, had some rain and it started to cut out and then be OK and then cut out usually below 2500 rpm, it then had a blinking session on the dashboard and then the handbrake light and the battery light stayed  on but no cutting out?? Battery is at 12.3volts when engine off and running idle 11.7v..??   which can't be right can it?   I thought it might have been my Dastek ecu connections getting wet but that was all dry as a bone.

Any ideas??  Thanks in advance

Lance.

[Call the midlife!]

Should be pushing 13.5-14 at idle with no auxiliaries on, have you checked the battery terminals for tightness and given them a dab of something appropriate before replacing? Or could you have disturbed one of the earths nearby?


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[tommytoneism]

Yes that's what i'm thinking...earth disturbation not a real word

OK any other ideas?

the belt though squeaking slightly is still turning..trying to stay cool

[Call the midlife!]

Yes that's what i'm thinking...earth disturbation not a real word

OK any other ideas?

the belt though squeaking slightly is still turning..trying to stay cool

The aux belts get noisy when they get old and tired, they get cracks across the inner surface which in turn "squeak" round the pulleys as it forces the air out of the cracks.


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[Carolyn]

Could also be squeaking 'cos it's struggling to turn the alternator because it's slipping or the alternator is seizing.

Either way, take the belt off and check how well everything turns.  Install new belt.

There's a 'how to' for that.

[tommytoneism]

Thanks Carolyn,

                          I'm changing the belt next week. Why do think it was intermittently cutting out prior to the lights coming on?

Thanks Lance

[Carolyn]

I can only guess at this range!

With voltage that low it would struggle to generate a decent spark.

[tommytoneism]

Thanks Carolyn,

                              I let you know how I get on.

L

                         

[tommytoneism]

OK,

              so I changed the belt tonight for a nice new Goodyear gatorback, and the lights are still on!!!

              Ive got 12.4volts  with engine off, and 11.7v when idling.

              Could it really be my alternator? easy to swap out? or is it a belt tension thing? I ask this because I was surprised that I didn't have to push that hard to get the tension off the belt.

              All thoughts welcome.

Thanks again,

Lance

[jonbill]

Sounds like a dead alternator to me.

[tommytoneism]

It feeling like that, but could it be the charging system fuse?

        do knackered alternators make noise?  slight rattle when revved

[lamcote]

Definitely, I once had a broken alternator and it sounded like ball bearings rattling round in a tin can. It started off happening occasionally but finished up happening all the time.

[Carolyn]

Sounds like a dead alternator to me.

Almost certainly correct!

Swapping out ain't 'easy' but not too bad of you go about it with a bit of patience.  Helps to remove the canister and then the top engine mounting bracket, so you can get at the two bolts that hold it in.  do the wires once the alternator is loose from its mounts.

If you look at the pic, you'll see one 12 mm headed bolt at the top (quite short) and one 14 mm headed bolt at the bottom (long and going into a captive thread - no nut at the other end.)  Those are the ones to remove.

[tommytoneism]

Hi Carolyn,

                Brilliant info thanks again, do you just take off the top part of the mount, bracket or the whole thing? Also do you have to prop the engine while your doing it?
                                                Thanks Lance

[Carolyn]

Just the top part.

No real need to prop the engine.  You can if you wish.

Take your time and enjoy the process.

[tommytoneism]

Thanks everyone for helping me out there again, particularly the amazing help and advice from Carolyn, thanks Carolyn :-) :notworthy:         


All done, and running better than ever, which brings me onto the question if the alternator has not been performing as well as it should, would it affect the performance? even though there's no misfires etc. I'm running a dastek piggy back??

Thanks again

lance

[Carolyn]

Well done.  That's a result!

If you were struggling for volts, enough to affect the spark, you would have had pretty obvious high rpm misfires.

I suspect the problem was bearings in the alternator, which finally went tight enough to make the belt slip.

If the belt did a lot of slipping, you might want to renew it soon.

[tommytoneism]

Thanks Carolyn,

                           I changed the belt for a goodyear gatorback, I'd heard good things about them.

Thanks again.

Lance

[Gaz mr-s]

Thread resurrection, - charging light on after start-up.  I last used the car 4 days ago, - did about 40 miles with a recently-replaced battery in the car, a higher-capacity that was fitted about 2 weeks ago.  It wouldn't have been fully charged, so the trip would have topped it up.

The car started no problem, but when I saw the light I left the engine running & checked the voltage, - under 12V. ??

If the battery was fully charged on the 24th then I would not have expected it to drop to 12.0V since it's new.

However today's measurement after starting the car & current being drawn from it is going to drop the reading....

The reason for resurrecting the thread is I also have the brake warning light, as the o/p had.  Why should it show, assuming no coincidence?

[Ardent]

If random lights start coming on, has often turned out to be the alternator.

[Gaz mr-s]

If random lights start coming on, has often turned out to be the alternator.

as mentioned by the o/p & myself....I'd like to know why.

[Carolyn]

Hey alternaors do just die!  Sounds like yours has given up the ghost. Bit of a pita to swap out.

[Gaz mr-s]

Hey alternaors do just die!  Sounds like yours has given up the ghost. Bit of a pita to swap out.

Damn.....rather inconvenient timing.  No fuse that could be gone....??

[Carolyn]

Damn.....rather inconvenient timing.  No fuse that could be gone....??

'Fraid not.

[Alex Knight]

Random warning lights is a sure sign that the alternator is goosed. Not just MR2s, but many other cars also.

Your battery is fine. Your alternator isn't.