Forums Forums Enthusiast Forums A - Z Autowirral Electrical problem

Brand new battery fitted This One fitted by RAC yesterday, alternator fully re conditioned, but at work last night, it got a bit chilly in car, so I put heater on full, and headlights went really dim, and if I came to a stop at traffic lights, the engine would come really close to stalling.

Now i know a bit about car electrics, but this has me stumped, I have checked alternator, and its kicking out what it should, I have cleaned all battery terminals, and all earth points, but yet it still carrys on.

Allso if the heater is not on neither iare lights, when am pressing breaks with foot on clutch, the revs drop and engine almost stalls.

Any ideas any one please. I's cracking me up. And I need my car for work.

Ford
Focus
1.6
16v
Zetec
Petrol

my bro can have a look for you if you want , been a mechanic for about 15 years

could be lamber sensor to air flow meter to engine idler to dirt in fuel line so mechanic is your best bet have you ever changed your fuel filter the is the most common problem should be change yearly or 30,000miles

All these parts have been replaced with new, RAC man has just been, he plugged his comp into car, no faults found everything as it should be, even he is baffled

its worth checking if you have a short circuit on either the heater motor circuit/ or the lights ?? starting at the fuse box first inc checking fuses are clean in properly etc !!

stick a voltmeter on yr battery without yr lights on or heaters and see what it reads , then switch the heaters on firstly and if voltage drops significantly then you have a short somewere
(although it will read slightly lower due to drawing more power from battery)

if it does have a short on one of these circuits it will be robbing your engine and ancilliries of much needed electrical power , hence it wanting to stall and the revs dropping

for example you ever put your rear windscreen demister on then you will notice the revs drop slightly on tickover ...
this is due to the huge current needed from the battery to power it

so if you have a direct 12v short on a circuit then this may have the effects you describe and also flatten battery v quick !!


sorry to ramble just hard to put into words hope you get it sorted mate

FORD = Found on Road Dead.

Check all earthing straps very carefully. Remove, clean up contact area to bright metal and re-fit. Look carefully for hidden ones underneath bits of the engine - chassis to gearbox for example.

Done all these yesterday.

Does any one know where I can buy 0 gauge battery leads from, as I want to uprate all battery leads on my car, as that is now the only thing that could be causing the power issue.

not sure if that's your problem? should have some thick stuff knocking around though if you want to chop it and stick some ends on.

are you around today? am at the garage in a bit if you want to pop in, to lazy to type what to try, easier to just tell you

Sent you a text.

garantee that wont help solve your problem mate !!
if they were inadequate from new then fords will have supplied the car in first place with 0 gauge leads mate ...

you would be better spending the money you are going to spend on them and taking it to an auto spark to have a quick look for you mate !!

do you know how to test for open circuits etc etc and do you have a decent multimeter ?????
if the answer is no to either of these points then i would take it to an auto electricians mate and im sure it will be a v easy fix for them mate ,you just need to understand how electrical circuits work and how to test them ...

google is yr friend also if you are on a budget mate

Looking at your post, although you mention the lights dimmed a bit when you put the heater on the main link seems to be your lights.

You say it almost stalled at the traffic lights, guessing your foot was on the brake pedal.
You say that the lights don't work properly when you press the brakes and clutch.
Heater needs to be on for lights ?

First things first, unplug the rear lights, if that solves your problem it's something to do with the light clusters (wrong bulbs in the brake lights, bad connection), if it's still the same then try unplugging the connector from the back of the light control switch (on the dash), take the lights out of the equation, and see what happens then.

Have not said this (You say that the lights don't work properly when you press the brakes and clutch.
Heater needs to be on for lights ?)

With MrHankys knowledge, I do believe the problem with high revving will be sorted on Wednesday, when I get new Head temp switch, and have fitted new thermostate, the ecu thinks the car is cold constantly so will not adjust revs, stuck on cold start due to faulty head temp switch which sits in head, inbetween plugs 2 and 3.

I have just bought a new thermostate, but can not fit it, as new coolent in halfords is too bloody expensive, 4 litres for £28.

failing anything else just go get a tin of petrol and nice big box of matches and job done !!!

saves any hassle lol

One day your saying take it to auto spark, the next day, set fire to car.

Make up your mind, you would not be condoning arson