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Alternator or Battery on the way out - tests.

J

Jamesy78

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Location
Hitchin
Car
56 Accord Sport
I am sick of alternators and batteries by now, had my wife's car, Mum's car and now my Accord all have battery/alternator issues within 2 months.
Mine is a little off though, but I will start at the start.

2006 Accord 2.2cdti sport, 85k miles.
Do roughly 2 trips of 30 miles a piece each day.

Now here is a contributing factor to these issues I believe, my boot light was parasitic drawing power for some time while my wife was using the car over a month or so, she did complain of some hesitancy starting a couple of times and flat battery once but I just blamed her lol. I fixed the issue with the boot switch but anyways am I right in thinking the battery getting flattened and almost flattened repeatedly might cause issues with it?

I got a Check System Light on this morning ( Non Charging Battery light )
When I got to work I went to see the site agents and borrow a multimeter.
Battery shows 11.6v so yeh ok the Battery could be the issue but it's only 2 years old from Honda (see above)
Start the car and check the Mulitmeter expecting to see a power drop from starting it or a boost from the alternator but I get no change at all still stuck at roughly 11.6v, turned on lights, still 11.6v, AC still 11.6v
So Now I am confused.... But being at work and already taking the **** I have had to come in and do some 'work' and just hope the car gets me home tonight 14miles journey.

Any thoughts or Gems would be appreciated as I have the car provisionally booked in for Thursday at Norton way Honda, I should have a few months left on battery warranty of 3 years I got when I bought it from them hopefully.
 
Sounds an awful lot like an issues I've had with my 2005 2.2 CTDI where my battery would go flat, even in mid-drive! It boiled down to an alternator clutch/pulley fault at the end, hence my car was only charging intermittently or not at all.

This looks like a good guide on working on the alternator
 
Voltage sounds low especially with a running engine, you could do with checking it at around 2.5k revs where it should show around 14.4v

If the battery is being flattened when left, have you got the hands free telephone system installed as that is known for sometimes draining the battery over night?
 
Yeh voltage should sit around 12.5v idle after surface discharge and 14.4v or so with the engine on.

It does so happen I have the Bluetooth phone system in the car and it hasn't worked for about a year or so though, hit the phone button on the wheel and ya get nothing.

James.
 
The official Honda system with the buttons on the steering wheel is known to sometimes go faulty and drain the battery. Try pulling the fuse to it if you suspect it is draining the battery overnight.
 
Well, down to Norton Way Honda they are saying ECU is reporting no voltage but they want £500 to do the job which is not happening.

Funny thing is the alternator is working a bit, I drove home in low gear the day I made this post and the check system light actually went out 3/4 way home and battery was at 13.1 (12.4 after I bled off the latent charge) when I tested it again so yeh.... looks intermittent, possibly the regulator
 
Yeh they are, but now you have Piqued my curiosity would the ECU still read an alternator as supplying 0 volts if the cabling to the battery was at fault?, at what point does the ECU read the output in the chain?
 
The alternator charges the battery not the ECU. So I would bed/borrow/steal an alternator either recon or used and go from there. Must be cheaper than chasing your tail looking at the ecu
 
Just an update, bit late but forgot my details.

Alternator was replaced and this cured the battery dying even with regular use problem but still after 4-5 days the battery drains if left unused.
I have a faulty hands free module in the car but I can't seem to find any information on where this unit is or how to disconnect it to see if this is the cause of the power drain.

I have a 2.2 Sport with the standard head unit/ac etc not an Exec with the nav system and I have no idea where the module is on the non exec models if anyone could shed some light that would be great as I have combed the net looking for any info.

James
 
Monitor the parasitic drain from the battery while pulling fuses one at a time... you should soon discover which circuit is drawing power when it shouldn't.

If you remove the HFT it will be harder to test.
 
O.K. Jon I will give that a go, seeing as it was broken anyways I thought it couldn't hurt to get it out and try the solder reflow while i was at it.

James.
 
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