Hi

Just wondered if anyone could shed any light on this

i have a 2.5T DI 53 plate transit recovery truck

Started the truck the other day and the battery light didnt go out like it normally does i stuck my tester onto the battery when engine off 12.5v approx and when engine running 15.5v approx so the alternator is charging the battery anyone know why the light is staying on ?

Cheers

Dave

 

15.5v?thats a bit high me thinks.normally charge around 14.3v.maybe regulator has gone in alternator and overcharging system and engine management is picking up on it and flicking light on

 

As said above, sounds like its overcharging, most likely an alternator fault.

 

Should be charging at 14.5v MAX mate,

 

Do these not have smart charging,check voltage with everything off,engine running,disconnect the multiplug and check again with heaters and demisters on,voltage shouldn't differ by 0.2 volts or the alternator is fooked

 

When this happens on the transit connect, its nearly always the 3 wire loom that goes to the alternator. The blue wire breaks, lighting the dash bulb and it also seems to put the alternator into a default charge setting.

I'd check the wiring first. It usually breaks at the terminal crimps in the alternator plug.

Thats of course if the Transit is similar to the connect in this respect.

 

Sounds like one of the diodes is about fail, in the good old days you could repair them, but these days.....

 

It will have smart charging

First things first, check the battery, not just condition, but correct type. A lead acid battery will not work properly with smart charge, it must be Silver Calcium! Easy to over look.



Next, put a meter across the battery. Remember when you remove the smart charge 3 pin plug from the back of the alternator, it reverts to a conventional alternator! If you do not have about 13.8 volts, carry out basic charging system checks and suspect the alternator, its not a smart charge fault !



Correct charge voltage from the alternator, then its time to start on the smart charge system, and you will need a scope. First the system.



Pin 1 = Alternator Feedback

Pin 2 = Alternator Load Request

Pin 3 = Reference Voltage



Now, pin3, must MATCH battery voltage ! Its fed from a fuse in the CJB, and a high resistance on the fuse contacts causes a volt drop, and the smart charge drops out !



Next pin 1 & 2 need checking back to the PCM for resistance, isolation from ground and each other. If ok, its out with the scope.



Pin 2 is the request from the PCM to the alternator. This will be a square wave pattern that will change with load request. So lights, screens etc on and monitor for a change in the pattern. (Obviously back probing with the plug connected)

No change in the pattern means no request from the PCM, you should now suspect a PCM fault. Correct pattern and move on.



Pin 1 is the feedback from the alternator and MUST remain a constant square wave pattern. If this pattern mirrors the one on pin 2, the smart charge part of the alternator is faulty, and a new unit is required.

 

Cheers for the replys i will try the above out

 

Excellent advice from davey8oy,
just to add that systems with CALCIUM batteries run up to 16 volts, this is normal, but the charge system is a lot more accurate to suit.
If originally fitted with a calcium battery it absolutely MUST only be fitted with a calcium replacement, a std lead acid one can explode due to the higher charge rate, but it is perfectly fine to put a calcium one in place of a lead acid with no harm at all.
tabetha

 

Excellent info mate

Martin

 

Sorry to revive an old thread but I'm having cold start issues. I just went and checked the battery voltage (used car few hours earlier) and it showed about 18v! Started car and was 15v and fully loaded was a tad lower. Obviously not normal voltage and I'll check what it is first thing and report back. Where should I be looking?

 

As it's "Smart Charge", the voltage can be around 16V as a general rule of the thumb. 18V does seem a bit high, but is it just a spike?

If you think there is a problem then you need to be looking toward the regulation.

Martin

 

No it wasn't a spike. Battery was sitting at about 18v. Was 15v after being left overnight which is when the car seems to struggle most.

 

Message for Davey8oy. Hi, I have read your post on the smart charging problem. 54 plate diesel T230 LX Ford Transit Connect. Red ignition light comes on after about 20 secs and stops on. I have checked the 3 pin smart charge lead and it checks out ok, I have not replaced it yet. Battery voltage is 12.67 when off. With the smart charge lead connected, after start up voltage goes to 13.8 but when the ignition light comes on it slowly goes down to 12.65 or less. The lights flicker and the engine hunts. If I remove the smart charge lead then the voltage goes up to 13.8 and is steady even with lights on.
Question:- can I leave the smart lead off permanently, will it do any harm. Is it likely to be the alternator ?

 

When you remove that 3 pin plug, it reverts to that of a conventional charging system, I suspect your problem may be the actual "Smart charge" part thats gone wrong, if the wiring is defiently ok.

I don't know, but I can't imagine it will cause any problems, I think people do this very thing when modifying, if they are changing to aftermarket management etc.

Martin

 

in my experience 90% of ford charging system faults are wiring related. how have you tested the three pin smart charge wiring? this section of wiring is about Ł15 and easy to rplace.

 

deleted my last reply just noticed the date on the post's

 

Thanks James. I replaced the 3 pin lead today with a new Ford one and got different results to yesterday. Now, with the lead disconnected I only get 12.6v with engine running, connect the new lead and I get up to 16.5v with engine running. Ignition light is still on. At one stage the light was off then started flashing. The mind boggles. From what I have read on the forums 16v can be accommodated, that is why we have to have the Calcium battery. Still looking for answers.
Happy new year
Roy

 

I would probably take a guess at and alternator fault in that case, unfortunatly for the connect it is right at the front, and we've had alot of rain/flooding recently......

 

Just checked the 20 amp fuse like Steve suggested, its ok. Checked the voltage again and low and behold its gone back to what it was yesterday, engine running 12.6v with the lead connected, 13.8v with it disconnected. What the hell is going on.
Rgds
Roy

 

As I said, I suspect the "Smart charge" side is faulty.

Martin

 

Do you mean the "Smart charge" side in the alternator or wiring/ECU

 

check the red wire in the plastic tubing that sit's on teh coolant fan cowling that go's too the alternator as the live wire rot's out and put's the battery light on the dash but doesnt discharge the battery

 

Steve, that lead was replaced today

 

was it the thin 2mm wire not the main thick live

 

I replaced the 3 wire lead (red/blue & grey, all about 2mm) that comes from the top/rear of the alternator up to a plug just under the intercooler.

 

only other thing i suggest is put a screw driver flat head type into the top of the alternator so you cant turn it and see if it turns on the belt side backwards if not the clutch is screwed in it do it by hand with a spanner/socket and ratchet on the crank pulley bolt

 

Mmmm thats a new one Steve, I will try that tomorrow. Thanks

 

p.s Steve, is the clutch in the rubber drive unit or the actual alternator ?

 

inside the alternator

 

Looks like a new alternator. Happy new year.