P38A ABS / TC fault appeared after sitting idle for 3 weeks

awkwardbob · Jun 27, 2022

-and if I have to fork out for a battery if the yakusa is pish (local technical term) what might be a good recommendation ? -bearing in mind the odd polarity

oakey · Jun 27, 2022

MF1000 from battery megastore £100 delivered

Flossie · Jun 27, 2022

Check the resistance readings on the good front sensor to compare? Plug is in the same place but the battery side.

Ratae · Jun 28, 2022

awkwardbob said:
So it looks like it’s on the ECU side abd, perhaps, does point to low volts

yakusa battery is 6 months old and reads 11.7V.

Going to put it on ‘boring’ charger to see if that helps,

feeling a bit glum

Major issue there. Fully recharge with a battery charger then, after resting, see if the voltage has improved. If it's still low then the battery has had it.
Any high drainage issues - faulty alternator, the P38 alarm issue?
A very rough guide to battery voltage: www.thebatteryshop.co.uk/car-battery-voltage-guide-34-w.asp

awkwardbob · Jun 28, 2022

But that’s two duffers in 6 months (last one replaced foc under warranty).

have I just fitted a badly-suited battery ? Or is it more to do with irregular use or improper charging (alternator currently o/ps 13.8V)?

Still, if £100 for a new battery fixes it, that’s getting off lightly

Ratae · Jun 28, 2022

awkwardbob said:
But that’s two duffers in 6 months (last one replaced foc under warranty).

have I just fitted a badly-suited battery ? Or is it more to do with irregular use or improper charging (alternator currently o/ps 13.8V)?

Still, if £100 for a new battery fixes it, that’s getting off lightly

I had issues a few years ago with Lion brand batteries on my Classic.
2 replacements during the warranty period & the last failed outside the warranty period (the warranty doesn't start again with each replacement, you get the balance remaining from the original purchase) & I replaced it with a different brand which was fine.
No issues with the vehicle charging system or a parasitic drain.
Chap behind the counter did say they got a lot of them back within the warranty period.

Grrrrrr · Jun 28, 2022

awkwardbob said:
But that’s two duffers in 6 months (last one replaced foc under warranty).

have I just fitted a badly-suited battery ? Or is it more to do with irregular use or improper charging (alternator currently o/ps 13.8V)?

Still, if £100 for a new battery fixes it, that’s getting off lightly

13.8V is no good for a high calcium battery. Anything with big CCA will have lots of calcium. That's on top of the usual RF issues.

kermit_rr · Jun 28, 2022

You can replace the voltage regulator inside the alternator.
VR-VW010 mobiltron

Datatek · Jun 28, 2022

11.7 volts is a dead battery that may not recover. 13.8 volts is not sufficient to maintain a lead calcium battery needs to be around 14.7 volts, as kermit said the VR-VW010 mobiltron regulator is what you want plus the MF31-1000 battery from Battery Megastore on line.
It's a waste of time trying to do diagnostics with low battery voltage.

awkwardbob · Jun 28, 2022

Datatek said:
11.7 volts is a dead battery that may not recover. 13.8 volts is not sufficient to maintain a lead calcium battery needs to be around 14.7 volts, as kermit said the VR-VW010 mobiltron regulator is what you want plus the MF31-1000 battery from Battery Megastore on line.
It's a waste of time trying to do diagnostics with low battery voltage.

Battery ordered (as specced) arriving tomorrow, I have in my greasy mitts the Mobiletron regulator so my first steps after work ce soir will be to safely remove the duff battery (as per Handbook: Ignition on, then off then remove within 17 secs) and the alternator and replace the VR on it.

I'm annoyed at burning another £100 on a battery but if it will save hours of grief on a wild goose chase, its money well-spent. I wonder if I can get a refund on the (second) dead one from Halfords under warranty.

awkwardbob · Jun 28, 2022

awkwardbob said:
Battery ordered (as specced) arriving tomorrow, I have in my greasy mitts the Mobiletron regulator so my first steps after work ce soir will be to safely remove the duff battery (as per Handbook: Ignition on, then off then remove within 17 secs) and the alternator and replace the VR on it.

I'm annoyed at burning another £100 on a battery but if it will save hours of grief on a wild goose chase, its money well-spent. I wonder if I can get a refund on the (second) dead one from Halfords under warranty.

I should clarify its the VR -f153A Mobiletron I have for my 120A Magnetti Alternator

kermit_rr · Jun 28, 2022

awkwardbob said:
I should clarify its the VR -f153A Mobiletron I have for my 120A Magnetti Alternator

Is that GEMS then? Thor uses a 150A unit

awkwardbob · Jun 28, 2022

kermit_rr said:
Is that GEMS then? Thor uses a 150A unit

yep Gems -for my sins

Datatek · Jun 28, 2022

Make sure you charge the new battery fully before fitting, it could take 24 hours

awkwardbob · Jun 28, 2022

Ok, so I’m in full dismantle mode…

battery is out, alternator is freed, mostly.

there were two cables into the back of it:

a meaty red one (presumably goes straight to the battery) and a feeble, thin cream
One.

I’ve released the wee one (the cable isn’t in great shape) but the red one is being BBC a jerk.

it’s one of those captive nuts and it won’t spin freely, it’s turning the cable too -and I’m not even convinced it’s coming off the terminal when it turns.

have any of you come up against this kind of thing before ? I’d have any advice on how best to free this pesky cable ?

thanks in advance !

Bob

kermit_rr · Jun 28, 2022

On mine (thor) the battery cable is a regular nut, the thin wire is a captive nut.
If you're not sure, mark the post with a pen and you'll see if it's turning with the nut

awkwardbob · Jun 28, 2022

Got it off but the bloody crimp connector cracked into bits.

guess I’ll be doing that next !

im going to stop tonight as I’ve nearly got the VR changed over but one cheesed screw is stopping me !

going to wait until tomorrow with fresh eyes and a deft flat-blade rather than bugger it beyond repair tonight !

awkwardbob · Jun 29, 2022

And the new VR is on !
The new battery is ‘out for delivery’
The VCU is at the post office awaiting collection.
And the heater matrix ‘o’ rings have arrived so that I can tackle the leak when I’m feeling brave.

I also have a couple of crimp ends for the alternator but was unsure of the cable diameter. I have a 25 and a 35 size crimped ring (sounds painful) so hopefully one of those will be chunky enough.

tonight’s work is to refit the alternator, install the new battery and re-attach the drivers seat.

tomorrow will be the hell of VCU and, if I’m feeling brave, some EAS work….

Flossie · Jun 29, 2022

Might be an idea to leave the drivers seat out, makes getting the centre console cheek off a bit easier and more room to do the O rings. Not a lot in it though but I'm tall and the seat was a hindrance a bit.

awkwardbob · Jun 30, 2022

So the alternator is updated, the cable end is recrimped (I used a size 16/10 Ring) and the new battery installed.

Voltage is healthy and 14.7 V with the engine running (up from 13.8V)

so far so good… but… the ABS / TC error (Front left sensor Open circuit) persists….

I’ll take her a short drive tomorrow and see if that clears it… fingers crossed

P38A ABS / TC fault appeared after sitting idle for 3 weeks

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