Last Problem - Battery Light Being Very Silly.

[AJRTDDI]

So when i brought the car i had a little battery light getting me stuck 60 miles from home at 3am. Very slowly dimming headlights.

Battery- Gone (lead acid) (replaced with a 075 Type new calcium battery)
Battery- Done
Alternator- Gone(replaced from europarts)
Alternator- Done
Alternator Plug (looks clean no breaks tested for breaks from pin to upto about 3ft)
Ground: (new grounds under battery/Engine and Gearbox) (Guage 0)
Grounds..Done


If i use no accessories, NO battery light + Charge (14.4-14.8) (90 Miles Fine Perfect.)

Headlights(full or mainbeam)/Heater on 3 - NO battery light + Charge (drops to 13.4 Slowly Creps back up to 14.0)

Headlights(full or mainbeam)/Heater on 3/Screen heaters - Battery light after a few seconds and No charge. (12.2 Then Drops)

Headlights(full or mainbeam)/Heater on 3/Screen heaters/AC - Light Instantly and Battery drains Instently (11.8 Then Drops)

Items underline keep the battery light on and will not Recharge itself. Note: If accessories turned off. The charge begins again (14,4-14.8) But Battery light stays on regardless

Any idea's guys :)

Normal driving is Fine. But when i have to go to work at 4am in cold and frost. I need the Headlight/Heater & Screen heaters :(

[JW1982]

The focus MK1 has a Smart Charge battery system. The alternator and battery light are fuly controlled by the PCM.

A short or open circuit between the alternator and the PCM or a defective PCM can also cause battery charging problems. 1 Wire of the 3-pole connector on the alternator should have exactly the same voltage as the battery. The other 2 wires are connected directly to the PCM. 1 Of these 2 wires is used by the PCM to control the alternator. The alternator generates an output signal on the other wire. The PCM compares this signal with the control signal and if the signals have too much difference the battery light will be activated.

If the alternator, Battery and wiring between the alternator and the PCM are in good working order the next suspect could be the PCM.

[artscot79]

The above figures are fine youre not meant to drive with heated front screen on if you were to rev to 2500 rpm those figures will rise so it could be a cluster issue its not the battery with the above figures its doing what its meant to

[AJRTDDI]

The volts dont raise by more then .2 of volts if at idle or 3,000Rpm. The Alternator seem's very effective

If i leave the car to idle. No Draw The battery light will still come on.

[AJRTDDI]

The above figures are fine youre not meant to drive with heated front screen on if you were to rev to 2500 rpm those figures will rise so it could be a cluster issue its not the battery with the above figures its doing what its meant to

what is the difference between driving and Idleing with heated Screens ? The current is still the same if not better because alternator will be spinning faster ?

[mgaking]

The above figures are fine youre not meant to drive with heated front screen on if you were to rev to 2500 rpm those figures will rise so it could be a cluster issue its not the battery with the above figures its doing what its meant to

Don't agree.

Sure my Focus stayed at about 14V even with the heated screen on.

Isn't that the whole point of the smart charge system. PCM knows the system load and adjusts alternator output to suit.

[AJRTDDI]

Don't agree.

Sure my Focus stayed at about 14V even with the heated screen on.

Isn't that the whole point of the smart charge system. PCM knows the system load and adjusts alternator output to suit.

Yea it's like the PCM is ignoring the load like the alternator is running at default

[artscot79]

the figures will be low with the heated front screen on it draws way too much power which is why its only meant to be used when really needed to test the figures you use only the headlights to on and rear heated screen on then write down the figures at idle and 2500 rpm the battery will not sit at 14.4 v with a front screen on and the point of smart charge is not what you think its purpose is simple a battery takes a better charge when cold so smartcharge detects a cold battery and puts 14.4 v into it as the electrolyte temp increases the smart charge lowers the charging rate of the battery no focus will sit at 14v with a front heated screen on thats a fact if it did youre over charging especially at idle if the battery or the elternator was at fault the fords designed so high draw appliances such as the screen at the front wont turn on so its not the alt or battery mate i gaurantee it as anyone will tell you i know my smart charge sysytems and the correct readings smart charge does not increase the voltage to compensate for the draw the alternator output is determined by the load on it and the speed it turns at so at idle with high draw its lower but press the accelerator and it goews up the reason you shouldnt drive with the front heated screen on is by the time you switch it off 5 minutes or so the draw on the battery is a heck of a lot youll bve lucky on a 30min drive to have replaced what has been used ford tell you to use it when needed and before moving off that way the battery has less load and can charge more effectively its a dash cluster fault or a break in the wiring somewhere its not the alt its not the battery

[AJRTDDI]

Maybe i should just change the Alternator 3 pin block as far back as possible in-case there a temporary break ?

[artscot79]

the alt in that case has rewverted to standard so the 3 pin connector is the likely culprit it must be intermittent as said the front heated screen shouldnt turn on in the case of the battery light being on ands not charging correctly its possible the alt you got is no use i know a few people who have had to get the proper ford alternator as the euro part ones dont have enough juice in them to work to save money it would be cheaper to have the car checked out there is a fuse in the under bonnet fuse box for the smart charge worth checking it just in case

[AJRTDDI]

Alternator:

Ecu pin 41 - Blue Wire
Ecu pin 45 - Gray Wire

For the smart charge ?

I don't have the money Atm, I am a mechanic but i am new to ford smart charge systems. Its simple to understand just sounds time consuming lol (this alternator is 100Amps (cheap ones was £80 this was £126 so i wasn't trying to be too cheap lol) Stock was only 80/90amp

[AJRTDDI]

The alternator puts out around 45/55Amps without Smart charge connected.

So as long as i don't run put much load on the car. It should be safe till Christmas is over ?

[mgaking]

Quick check on my Fiesta.

With lights and heated front screen on it sits at 13.8 - 14.0V at idle.

[AJRTDDI]

Quick check on my Fiesta.

With lights and heated front screen on it sits at 13.8 - 14.0V at idle

mine is same. with just Dipped Beams and front screen on

Don't forget mine is Heated Front/Rear/ Both Wing Mirrors).

:) Sounds like my alternator is running at 1/2 of its load.

looks like ill have to go looking for the ecu and find the wires that run to the alternator.

[mgaking]

Another quick check.

Heated front screen + heated rear (which includes heated wing mirrors) + headlights + fan on 2.

13.7 - 14 at idle.

Doesn't actually help you though.

Was the alternator an RTX one? Google search suggests they are not good.

eg

http://fordtransit.org/forum/viewtopic.php?f=54&t=112799&start=15

[AJRTDDI]

Another quick check.

Heated front screen + heated rear (which includes heated wing mirrors) + headlights + fan on 2.

13.7 - 14 at idle.

Doesn't actually help you though.

Was the alternator an RTX one? Google search suggests they are not good.

eg

http://fordtransit.org/forum/viewtopic.php?f=54&t=112799&start=15

Yes it was a RTX mine will die to 12v and light doing what u said above^

[artscot79]

above is about right if youres is dropping way down to 12v and again i said the test should be done with headlights and rear heated window not the front to get a proper reading if its 12v then the alternator you got is either no good or as said the 3 pin plug has a broken wire did the original alternator work when you switched it over what battery was it exactly is it the correct rating and amp for the car you say it had a lead acid battery to start with this may have caused the smart charge fuse to blow after a time given smart charge complexity it needs looked at on an oscilator to check the wave form data ford do this other places usually look at you like an alien when you mention smart charge ide have it checked or youll end up with a duff battery a non starting car and then need a new battery and change the wiring then alternator again to find the problem ive found in the past some of these alternators you get are just not good enough ive had it myself on the mk1 worked great for 2 days in the end it was said to be for the car but wasnt the correct rating and didnt pump enough juice out

start at the begining check the data on the old alt with the new one check the battery is the correct one for the car check the smart charge fuse look at the 3 pin plug see if any wires look to be pulled after that youre choice is to replace the 3 pin plug with one from ford but beware in the past these have been broken behind the wheel arch and not at the plug hence why i said its easier to have it looked at properly

[artscot79]

the 4 smaller wires which come from alternator, two
of which go to the ECU, and the
signal to the indicator light on the dash comes from the ECU.

the light can indictate a false negative, due
to a break in one of these thinner wires from the alternator to the
ECU.

on the red wire just one inch
from the plug/connector is the most common place for the wire to break

also check the red wire to the underbonnet fuse box f10 thats the smart charge wire and fuse

[AJRTDDI]

above is about right if youres is dropping way down to 12v and again i said the test should be done with headlights and rear heated window not the front to get a proper reading if its 12v then the alternator you got is either no good or as said the 3 pin plug has a broken wire did the original alternator work when you switched it over what battery was it exactly is it the correct rating and amp for the car you say it had a lead acid battery to start with this may have caused the smart charge fuse to blow after a time given smart charge complexity it needs looked at on an oscilator to check the wave form data ford do this other places usually look at you like an alien when you mention smart charge ide have it checked or youll end up with a duff battery a non starting car and then need a new battery and change the wiring then alternator again to find the problem ive found in the past some of these alternators you get are just not good enough ive had it myself on the mk1 worked great for 2 days in the end it was said to be for the car but wasnt the correct rating and didnt pump enough juice out

start at the begining check the data on the old alt with the new one check the battery is the correct one for the car check the smart charge fuse look at the 3 pin plug see if any wires look to be pulled after that youre choice is to replace the 3 pin plug with one from ford but beware in the past these have been broken behind the wheel arch and not at the plug hence why i said its easier to have it looked at properly

Thats why i said i'll check the wires from the ecu to the plug. If theres a break between them i'll build a standalone loom to replace. ( i posted 2 ecu pin numbers to see if anyone knew if they was correct)

Unit removed was a Magneti Marelli 90Amp.

Unit replaced was RTX Alternator 90Amp (http://www.eurocarparts.com/ecp/c/Ford_Focus_1.8_1999/p/car-parts/car-electrics-and-car-lighting/electrical/alternator/?401591302&1&78bd3defd892c614fc9ed963472699c63b04f89e&000012)

battery on the car was a Type 075 so that is what i replaced it with. But a friends focus as a type 100 battery.

headlights and rear heated window gets 13.8V (no heater ect)

Smartcharge fuse still asnt been found. currently looking in haynes manual

Not sure if this is related. I had a H7 Bulb bloat out and burn out on me yesturday. i had to smash it to remove it from the holder. It had only been fitted and used for about 2 hours

[AJRTDDI]

battery light come on 4 times going to work ( northing but headlights on)

[AJRTDDI]

the 4 smaller wires which come from alternator, two

of which go to the ECU, and the

signal to the indicator light on the dash comes from the ECU.

the light can indictate a false negative, due

to a break in one of these thinner wires from the alternator to the

ECU.

on the red wire just one inch

from the plug/connector is the most common place for the wire to break

also check the red wire to the underbonnet fuse box f10 thats the smart charge wire and fuse

the 4 smaller wires which come from alternator, two

of which go to the ECU, and the

signal to the indicator light on the dash comes from the ECU.

the light can indictate a false negative, due

to a break in one of these thinner wires from the alternator to the

ECU.

on the red wire just one inch

from the plug/connector is the most common place for the wire to break

also check the red wire to the underbonnet fuse box f10 thats the smart charge wire and fuse

i only have a big wire (power) and 3 pin block i think.

[Nathan_M]

It's obviously the fact that the alternator isn't being asked for charge more than the fact that it's not effective.

Sent from my GT-N5110 using Ford OC mobile app

[AJRTDDI]

i just been making sure to turn heated screen off before i use my headlights and asnt happened since. Its a pain in !Removed! but atleast it charges my batteryish.

[Nathan_M]

I didn't realise you were running with the heated screen like that, it uses an enormous amount of power a good example of this is to turn the heated screen on and then put the fan to number 4 it can only supply the power to run the fan slowly the minute you turn the screen off the fan speeds up its literally just a case of not enough power to go around.

Sent from my GT-N5110 using Ford OC mobile app

[AJRTDDI]

front screen maybe faulty cause only half works.