Fitted New Radio - Flickering Headlights - 02 Focus

[matthewl]

Hi,

Last weekend I replaced the factory stereo in my 2002 1.6 Ford Focus, with a new one.  Nothing special, just a Sony CDX-GT564UI.

Everything seemed fine, but on the way in to work on Monday the headlights and dashboard started flickering constantly.  I put it in test mode on the way home, and after about 15 minutes at 14.5 the alternator reading began flicking between 11.5 and 15.5 - with the lights flickering to match.  Towards the end it sat at 11.5 and the battery warning light came on.

I pulled the radio and drove in test mode today, and apart from a few blips when idling the reading sat at 14.4/14.5.


Am I just at the limit of what the alternator can put out, or would a short-circuit somewhere have the same effect?  The battery light has come on a few times before so the alternator could be on its way out, but I'm surprised that the radio has such a massive effect.

 

[NozSpark]

Check your battery terminals,,, I had a similar(ish) problem recently and found a corroded negative terminal.. After giving it a good clean with some wet & dry and smearing a bit of grease over it before reassembly the problem has now gone

 

[kerching]

car  electrics can be a strange beast.....

an employee once decided to replace a lamp in one of our vehicles...not that tricky if you have a brain cell.

however he fitted the wrong lamp

could not work out why people kept pulling out in front of him at junctions/traffic lights

the wrong lamp and a dodgy earth had caused the headlights to flash whenever he touched the brake pedal

other motorists thought he was flashing them, so they pulled out

not that this has helped you with your radio, but it goes to show how weird car electrica are

just saying

 

[brycenesbitt]

There's also a screw connection from the negative battery terminal to the chassis.  This one gets worn out since some techs remove it when servicing electrics.  Check it is secure, if rusty shine it up and maybe add a light touch o'grease.  

 

[Wilpickard]

When ford launched the focus in 98 they started using a smart charge system. This will ramp the voltage up to 16-17 volts to charge the battery while cold, while working on these I found if you had a non genuine or non calcium battery fitted you would often notice the lights flicker.

I'm sure if you fit the correct battery the problem will go away.

On later cars they switched the headlamps to run on a PWM signal to try and regulate the voltage, customers then complained that they could see the lights flicker in the corners of thier eyes, a little like fluorescent lamps

Ive been out of the motor trade for a few years now but that model was about when I did my masters so know it pretty well.

Feel free to message me and I'll do my best to pass on any help or imformation (as long as I can remember)

 

[matthewl]

Thanks for the quick replies (I was waiting for an email to say that someone had responded).

The battery terminals show a bit of corrosion.  I haven't looked at a lot of batteries, but I'd guess it's in the "Ok, but could do with a clean" category.

The connection to the chasis is looking fairly ropey in places.  Hopefully I can still end up with a good connection.

I'll also look-up the type of battery installed.

I think there's a bit of cleaning to do this weekend.

Cheers.

 

[matthewl]

Just to wrap things up in case anyone else has the same problem.

I tried cleaning all of the connections.  There might have been an improvement, but the flickering was still there.

I probably should have said that I had a multimeter.  I checked the battery voltage idling and under load, and it seemed like the alternator just couldn't output enough.  Although I should probably have revved higher to be sure.

Anyway, I had the alternator replaced, and the flickering went away.  Then replaced the battery.  At least I'd ruled out the cheap fixes first.

Thanks.