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General >> Problems >> Charging problem
(Message started by: Paul_Boulden on Jul 9th, 2006, 8:19am)

Title: Charging problem
Post by Paul_Boulden on Jul 9th, 2006, 8:19am
1996 2.9 12v, auto, 158,000 miles.

For several years the battery light on the dash has been glowing faintly, this was assumed to be a failing diode pack.

Two weeks ago ( at night ) the alternator appeared to fail, first symptom was the rev counter only registering under acceleration. The car ground to a halt at the roadside so the battery was removed and charged overnight. Next day battery was refitted and car driven to a garage who replaced the alternator.

All seemed fine except the battery warning light comes on, only faintly and after a couple of minutes. Then the rev counter started intermittently playing up again and yesterday the dash needles flicked over on sart up.

Battery voltage reads 12.6 ( 13.7 with engine running ), has been charged up.

Is there anything I can test easily before trying to take it back to the garage ? I am sure they will say that the battery is broken but could they have fitted the wrong alternator ?

Thanks in advance

Paul Boulden

Title: Re: Charging problem
Post by Snoopy on Jul 9th, 2006, 8:40am
The battery light coming on after a few minutes is a sure sign that the diodes are failing in the alternator.
My advice would be to get it replaced under warranty ASAP.
If the battery needed recharging then the alternator would definitely seem to be faulty

I think the flicking rev counter would seem to signify that the alternator provides the pulse for the rev counter but I thought that was only on the TDi model.

Others might know more.

Title: Re: Charging problem
Post by sector-9 on Jul 9th, 2006, 10:51am
The diesel uses the crank sensor for the rev counter input - there's no connection to the alternator.


Darren

Title: Re: Charging problem
Post by manscorpio on Jul 9th, 2006, 11:13am
Paul
Long shot, but problem could be same as mine - see Cosworth R19 Run Relay..... post.
I have the glow from gen light unless R19 is removed.

Title: Re: Charging problem
Post by Paul_Boulden on Jul 9th, 2006, 5:37pm
Thanks for all help so far, I have recharged battery, removed R19 and the engine runs OK without glowing warning light. Replace R19 and battery warning light glows dimly.

This raises more questions, if the only problem is in the R19 circuit would this explain the previous problems ?

What does R19 do and why would it make the battery / charging light glow ?

What is the fault with R19 likely to be and how do I check / solve it ?

Cheers,

Paul


Title: Re: Charging problem
Post by manscorpio on Jul 9th, 2006, 7:34pm
Paul
Don't know, I have had the problem since March and all Scorpio brainpower has not cracked it - Darren has got closest I think, problem somewhere in the charging circuit. Interestingly my problem only really appeared when new battery was fitted. There was no glowing light before..............
Ian

Title: Re: Charging problem
Post by Paul_Boulden on Jul 9th, 2006, 7:56pm
Hi Ian,

I note from your thread that you had a massive current drain, whilst I appear to have a drain it is not massive.

Do you have any problems ( apart from no aircon ) running with R19 removed ?

Paul

p.s. the relay seems OK

Title: Re: Charging problem
Post by manscorpio on Jul 9th, 2006, 9:22pm
Paul
I have not actually measured the "massive" current drain - it could be very small; my thinking was, at the time, that for the gen light to be on it MUST be massive, because of the very large output from the alternator. I have since realized that the light comes on for a variety of reasons............. The only way I notice a problem with R19 removed is that the air con does not work because the clutch on the air con compressor does not engage.  There may be other things that do not work but they can't be very important or I would have noticed.

Title: Re: Charging problem
Post by sector-9 on Jul 9th, 2006, 11:10pm
According to the manual, R19 is used for the engine management system (small brown relay right?), but I can only find a kick-down relay on the wiring diagram for the 12V 2.9i which I don't think is it.

Unfortunately the wiring diagrams for several key circuits such as charging system are missing from the Russian website linked to on the main site so we can only guess at what the circuit should look like.  Certainly the battery warning light will connect to the alternator, and if there is an engine-run relay (though there aren't any called that in the handbook) then the alternator side of the lamp will connect to one side of the relay coil and the other will be grounded.

Leave it with me and I'll trace what fuse powers the switch contacts of R19 - that might give us a clue, in the meantime, try every circuit and electrical function your car has to see if anything else is affected.

Darren

Title: Re: Charging problem
Post by Simmo on Jul 10th, 2006, 5:10am
Ian/Darren, have you found this page ? http://www.fordscorpio.co.uk/electsystemtest.htm.

Title: Re: Charging problem
Post by Paul_Boulden on Jul 10th, 2006, 10:12am
Hi Darren,

Yes, R19 is a small light brown relay, I have started the car today ( no flicking needles ) but not had chance to take it for a run. The only thing I can see that isn't working is the heated front screen ( no light on the dash ).

It is idling too high and the trip diagnostics show "pulses" at about 220, "batt." 13.6 - 13.7 at idle ( no change with more revs ). I assume that after a run the ECU should re-set itself and the pulses / idle return to normal.

I will go to the garage today to pay for the alternator and will check that they have fitted the correct type / output.

Thanks

Paul

Title: Re: Charging problem
Post by Paul_Boulden on Jul 10th, 2006, 5:24pm
UPDATE

Started the car to go to garage, needles flicked over. On the journey all went well, everything I can check seems to work ( not aircon or heated front screen ) including kickdown.

Garage checked alternator was correct type and the battery is fine. Rev counter needle has stuck once on start up, worked OK after revving.

Strangely the needles seem more likely to flick around if the engine has run for a while and is quickly restarted. Also, before this problem, I had regular, intermittent, warning lights for ABS ( usually disappears after restart ) and Airbag light ( flickering ), not happening now ( presumably as a result of removing R19).

What next ?

Any suggestions ?

Thanks,

Paul

Title: Re: Charging problem
Post by Tompion on Jul 10th, 2006, 5:42pm
Paul

Just in case you don't know the needles will flicker next time you turn the ignition on after doing a trip diagnostic.

Dave

Title: Re: Charging problem
Post by Paul_Boulden on Jul 10th, 2006, 5:53pm
Hi Tompion,

Didn't know that - thanks.

Do you ( or anyone ) know exactly what the flickering needles mean ( other than just a battery problem ) ?
Also, is the trip diagnostic using the same senders as the various guages and warning lights ?

Thanks,

Paul

Title: Re: Charging problem
Post by sector-9 on Jul 10th, 2006, 10:12pm
Indeed they do use the same senders.  As you are having multiple seemingly-unrelated electrical problems I would definitely check the wiring loom for problems.  Can't remember where but I think I read that the loom chafes on the cylinder head on the DOHC?

Also, with the light coming on dimly after a few minutes this could be down to the terminal voltage of the battery dropping from 13.xV down to it's nominal 12.xV - it's a pretty wild guess but it might be worth taking voltage readings across the battery terminals immediately after switch-off and again when the light is on.  If there is a definite change in voltage then check what it is between ground and the small terminal of the alternator - I would expect there to be no voltage reading with the ignition off - if there is then it could be the voltage regulator on the alternator itself in which case disconnecting the thin wire from that terminal should turn the light off.  Don't leave it disconnected though otherwise the alternator won't work!

Darren

Darren

Title: Re: Charging problem
Post by manscorpio on Jul 10th, 2006, 10:47pm
Paul/Darren
I am away from the car for a week so cannot progress investigation of the fault.
However it is possible that the front screen is not working, but the dash indicator came on, but, being a hot day it was very difficult to confirm that it was working.
I thought incorrect alternator but no, confirmed by Ford dealer. My engine is running very nicely, touch wood, thank-you - very stable tickover and no wild dials.
I have noticed a new problem just recently, which I am sure is not connected as I say only recently occured, and that is the fuel economy computer is not working properly. The instantaneous consumption is consistently at 99.9 which has a major impact on the average consumption figure. (39 mpg from a cosworth!).
Reading the article Simmo referenced my light, as I recall, glows dimly all the time. Dimly though is relative -  in bright sunlight it is very difficult to see but in the dark iti s much more obvious. I think that Darren's latest theory is probably correct - chafing in the loom somewhere. My only real nagging concern is that my problem only appeared after new battery fitted. The presence of the light then suggested new alternator, but even this did not fix the problem.  

Title: Re: Charging problem
Post by Paul_Boulden on Jul 10th, 2006, 11:15pm
There seems little doubt that my alternator needed replacing, I have also noticed that four rear bulbs need replacing, one of them has turned silver - it almost looks as if it has been chromed !

I have not noticed any loom damage but I will have a look ( remember it's a 2.9 12 valve not a DOHC ). When I can I will replace the relay and check for voltage changes as the battery warning light comes on.

Thanks all

Paul

Title: Re: Charging problem
Post by Paul_Boulden on Aug 29th, 2006, 8:13am
The saga continues !
I found some wiring damage ( looked like a mouse had got into the fusebox ) and eventually taped it up as best I could. I refitted the relays ( R19 and one in the glovebox for the aircon ). After about a week ( daytime driving only ) the battery went totally flat - the engine would not turn over, no window motors etc. After a few minutes the engine fired up and I made it home, charged battery overnight, removed the relays again.
All seemed OK for another 10 days when the battery flattened again.
I recharged it overnight, this morning all seemed OK but the alternator light is glowing again.

All this time the rev. counter is erratic, not working for most of the time, often causing massive radio interference.

Could a failing battery battery cause the alternator light to glow ?

Is there any common component linking the charging circuit to the rev. counter or could this just be a coincidence ?

Thanks for any help / suggestions.

Paul

Title: Re: Charging problem
Post by solarpanel on Aug 29th, 2006, 6:58pm
my cossie did this the battery went flat etc found the wiring harness from the main fusebox down by the brake servo to the multi plug on the inner wing was getting warm peeled the casing off ......rotten wires by the bus load,rewired it .....sorted hth

Title: Re: Charging problem
Post by Paul_Boulden on Aug 29th, 2006, 7:59pm
Hi Solarpanel,

Thanks for the input, did you have any rev. counter issues ?

I will check the wiring tomorrow before I take it to the garage.

Thanks,

Paul

Title: Re: Charging problem
Post by Paul_Boulden on Aug 30th, 2006, 4:39pm
Update

Returned car to the garage, it seems the new alternator was faulty, it has been replaced and things are OK for now

Thanks for the help

Paul



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