Disco 2 Battery charger error!!

sofie 2 · Feb 9, 2019

After a long job replacing steering ball joints, I put the battery on charge and the horn/alarm sounded immediately. I had put the charger clips on the wrong terminals!
Everything works/lights-up, but the starter won't turn. All the fuses/fuseable links are OK.
I've had the ECU checked by an expert. I suspected that the BCU has cut-in and I entered the EKA code. Doing that has not cured the problem, Putting a meter on the relay sockets, I get a constant 12.5v off the starter motor socket and 12.5v off the BCU socket when switched to crank. One thing that I don't understand is that I don't get any voltage off the main feed to the relay, even though the fuseable lik is OK.
It was a stupid mistake to make. but I'm sure that I'm not the 1st to do it and I won;t be the last one.
I'd be grateful for any advice.

sierrafery · Feb 10, 2019

What happens if you remove FL12 and bridge the perpendicular cavities in the fusebox? (off course make sure it's out of gear)... did you check the FL for continuity with multimeter too cos there are cases when it's invisible hairline crack in them

sofie 2 · Feb 10, 2019

sierrafery said:
What happens if you remove FL12 and bridge the perpendicular cavities in the fusebox? (off course make sure it's out of gear)... did you check the FL for continuity with multimeter too cos there are cases when it's invisible hairline crack in them

Hi, Thanks for your input. There is 12.5v at FL12 terminal. The fuse passed the continuity test. No continuity between the other FL terminal & the relay terminals. Tried removing the fuse box to check the wiring, but the aged wiring underneath, was keeping it in place & I didn't want to create a new problem by damaging them. I'm using the Haynes manual wiring diagram & I'm wondering if the details are correct.
Terminal 30= no volt 86= 12.5v on crank only 87= permanent 12.5v 85=no volt
86 is the BCU connection. 87 is the starter connection - It doesn't make sence.

sierrafery · Feb 10, 2019

If you remove the relay and bridge the perpendicular cavities(30 - 87) the starter should kick in, if it doesnt and you have voltage on that bridge the problem is between the relay and the starter, can be in the fusebox's connector or within the fusebox, if it kicks in this way it's something with the coil's command, here's a clear diagram edited by me ... the thing is that 30 and 87 or 85 - 86 can be the other way around important is the contact to close and to have feed on it which means 12V across 85 - 86 on crank

sofie 2 · Feb 12, 2019

Hi, Thanks for your advice & the diagram. I've spent more time on the problem today and I think that I must have 'fried' the BCU or something, when I put battery charger clips on the wrong way round. I presume that's why the alarm/horn sounded.
I was curious if other ccts were OK and removed FL13.[ It feeds the lights etc], and everything seems OK, but what I did find is that the 12.5v I've been getting off the starter solenoid terminal [87],which is on FL 12, stopped when FL13 was removed.
STARTER RELAY TERMINALS:
30 Main power in - no voltage
85 Ignition switch supply to the coil - no voltage
86 Feed to the BCU - RECEIVES 12.5v on crank only
87 Feed to the solenoid - RECEIVES PERMANENT 12.5V
What a mess!!!

Colthebrummie · Feb 12, 2019

Might be a daft question, but have you tried disconnecting the battery?

Col

sierrafery · Feb 12, 2019

sofie 2 said:
STARTER RELAY TERMINALS:
30 Main power in - no voltage
85 Ignition switch supply to the coil - no voltage
86 Feed to the BCU - RECEIVES 12.5v on crank only
87 Feed to the solenoid - RECEIVES PERMANENT 12.5V
What a mess!!!

The mess is made by you by the way you do it. Read again carefully what i wrote in my previous post and do that bridge cos i told you that 30 - 87 and 85 - 86 can be the other way around !!! (it happens in diagrams) and from these measurements of your's it seems that you dont understand what i meant nor how this should work cos as you said "86 Feed to the BCU - RECEIVES 12.5v on crank only" is a wrong conceprtion as there is NO feed to te BCU but earth switched to the relay coil by the BCU ... also QUIT MESURING ONLY VOLTAGES AGAINST EARH IN THE CAVITIES, make that bridge as i told you also measure for foltage ACROSS 85 - 86 with ignition on and as long as you have crank voltage on 86 the earth from BCU should come to 85 and if it isnt that's your problem... the diagrams in RAVE are not 100% accurate all the times but the principle is so based on your voltage measurements nothing wrong untill now voltage wise and here's re-edited how it is in reality :

sofie 2 · Feb 12, 2019

Hi Col, Thanks for your input. I disconnected the battery and charged it.
Hi Sierafery, I can't return to the problem today, but will follow what you say in the next day or so.
I know that I shouldn't get 12.5v from the BCU , but that's what I'm getting. Could be that the switch in the BCU is stuck in the wrong position.

sierrafery · Feb 12, 2019

sofie 2 said:
I know that I shouldn't get 12.5v from the BCU , but that's what I'm getting. Could be that the switch in the BCU is stuck in the wrong position.

I think you are not listening or you dont concentrate enough, take your time and think well to all i said untill now... i doubt that you are getting 12.5V from the BCU cos 86 where you get this is from the ignition switch that's why i reedited the diagram

sofie 2 · Feb 18, 2019

Hi, On Thursday, I made a bridge between terminals 30 & 87. No start, so I checked continuity at the block terminal. That was OK. I then jacked the van up & saw that the wire on the solenoid spade wasn't pushed fully home. Checked for continuity and it was OK, so I cleaned the spade & pushed the connector fully home. Removed the bridge & fitted the relay. Put the key in & she fired-up straight away! COULD'NT HAVE BEEN HAPPIER IF I HAD WON THE LOTTERY & EURO MILLIONS ON THE SAME DAY.
Lessons learned: The control unit only lets you know if you have reversed the polarity & doesn't damage it.
Don't trust the wiring to be as per the diagrams
Many thanks for your input..

Disco 2 Battery charger error!!

sofie 2

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sierrafery

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sofie 2

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sierrafery

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sofie 2

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Colthebrummie

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sierrafery

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