Flat battery :(

Technical questions and answers about the Mazda Bongo

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sotal
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Re: Flat battery :(

Post by sotal » Sat Jul 30, 2016 7:04 pm

Right traced the wires from the relay and I can see where the problem lies.

The wire which I thought would go to the alternator to activate the relay doesn't go to the alternator. Instead it takes its feed from the radio circuit inside.

I'm sure you can see where this is going!

Last year I made up a harness to move all the necessary circuits over to the LB. Obviously one of those was the radio/cigarette lighter socket circuit (think they are the same one). Thus connecting the relay to the LB telling it to charge all the time!

Taking that wire out of the fuse box and putting a fuse back moves the radio and the cigarette lighter socket back over to the SB and then the relay deactivates when the Bongo is turned off but as soon as the key is turned to ACC it activates the relay.

So now I know what the problem is I need a new answer!

Where should I connect that wire from the relay to? Is there an easy point to pick up the alternator wire from?

It is currently connected via a scotch lock (I never use them) right behind the drivers knee fuse box.
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sotal
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Re: Flat battery :(

Post by sotal » Sat Jul 30, 2016 7:40 pm

Have searched the wiring diagrams and can't find the wire I'm after :(

Tempted to order a VSR as it doesn't need that extra wire! Or maybe just put a switch in so it only charges the LB when I flick the switch.

Got to say I'm surprised it was that though as it means they've been linked like that for ages! Surprised I never had a flat battery before!
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sotal
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Re: Flat battery :(

Post by sotal » Sat Jul 30, 2016 7:58 pm

Used the old fashioned way and used the multimeter.

I've given up on the alternator feed but figured that as it used to be connected to the radio circuit behind the fusebox. I just need to find another circuit which is still on the SB and only live when the key is turned.

The on 2nd row down, 2nd in from the left (Dashboard 15A) seems to fit the bill.

Can you see any problems with connecting to this one?

Thanks
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sotal
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Re: Flat battery :(

Post by sotal » Sat Jul 30, 2016 8:25 pm

All connected to that wire and all seems to be functioning correctly.

I removed the scotch lock and properly soldered/heat shrinked the wire in place.

Only extra thing I noticed was that the Haydn Coolant alarm is also connected to that wire.
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g8dhe
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Re: Flat battery :(

Post by g8dhe » Sat Jul 30, 2016 9:07 pm

The one going to the Alternator signal wire will indeed show +12v with the Ignition ON, it will only go low when the alternator is not turning (or has a fault).
This is why you get the Charge lamp slightly on with this type of connection.
Geoff
2001 Aero V6, AFT, full side conversion.
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sotal
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Re: Flat battery :(

Post by sotal » Sat Jul 30, 2016 10:00 pm

g8dhe wrote:The one going to the Alternator signal wire will indeed show +12v with the Ignition ON, it will only go low when the alternator is not turning (or has a fault).
This is why you get the Charge lamp slightly on with this type of connection.
I never found the Alternator signal wire.

The relay was connected to the radio circuit which I had moved to the LB (hence the issue).

I have now connected it to the Dashboard circuit - which seems to function correctly.
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Re: Flat battery :(

Post by g8dhe » Sat Jul 30, 2016 10:24 pm

You need to pick-up the IG2 circuit after a fuse;
See the ignition switch, top centre and then choose a fuse driven from it;
Geoff
2001 Aero V6, AFT, full side conversion.
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sotal
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Re: Flat battery :(

Post by sotal » Sun Jul 31, 2016 1:51 pm

Thanks for that.

Can I ask though why does it need to be IG2?

Originally it looks like it was installed on ACC, which worked well enough until I moved ACC to the leisure battery.

Now I have moved it to IG1. Is there anything wrong with it being on IG1 rather than IG2?


Also, I'll be going away soon and am a bit worried that the capacity is going to be somewhat reduced if I've spent the last year using both batteries linked when camping! I have a digital read out of the voltage of the LB on a cigarette lighter plug. What voltage should I avoid dropping below?

Thanks
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g8dhe
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Re: Flat battery :(

Post by g8dhe » Sun Jul 31, 2016 5:24 pm

IG2 is powered ON (thus linking LB to SB via SCR) during engine running but NOT when starting, you don't want the LB to partake in that operation! You then also have the advantage that should you ever leave Headlights on or otherwise flatten the SB, if you leave it in the ON (but not starting position) but without the engine running for 20 minutes or so then you can let the LB charge the SB to get you out of an awkward spot without needing a jumper lead as well!
Once the engine is running and the alternator is spinning then both batteries will be charged as you expect.
Geoff
2001 Aero V6, AFT, full side conversion.
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sotal
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Re: Flat battery :(

Post by sotal » Sun Jul 31, 2016 6:11 pm

So is it safe to leave as is on IG1 for a couple of weeks until I get round to it.

I take it as it was on ACC for years, then due to me swapping ACC to LB - they were both connected all the time - a couple more weeks not quite correct shouldn't cause much problem should it!

I'm surprised it doesn't melt the little wires if it does try to use the LB when cranking the engine.
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Re: Flat battery :(

Post by g8dhe » Sun Jul 31, 2016 10:27 pm

IG1 is NOT a good idea! That means its operating at all times, you will kill the LB in quite short order especially if you need to crank the engine for any length of time.
Geoff
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Re: Flat battery :(

Post by sotal » Sun Jul 31, 2016 11:12 pm

g8dhe wrote:IG1 is NOT a good idea! That means its operating at all times, you will kill the LB in quite short order especially if you need to crank the engine for any length of time.
Was it not just as bad when it was on the ACC before? And even worse given the fact that since I moved the radio circuit to the LB last year it has been linked 24/7?
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Re: Flat battery :(

Post by g8dhe » Mon Aug 01, 2016 9:43 am

No ACC is not powered during Starting so the LB won't have been contributing to the starting effort.
As to having it switched over to the LB , then it will have been operated all the time which is probably the cause of your problems in the first place thinking about it.
Geoff
2001 Aero V6, AFT, full side conversion.
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Re: Flat battery :(

Post by sotal » Thu Aug 11, 2016 1:22 pm

Thanks for taking the time to explain,

I have moved it over to IG2 on Fuse 9 - think it is Aircon/Heater fuse.

All seems to carry on functioning well.

I think the LB is a bit worn though, it is normally at about 12.8v after a good run, but it then loses 0.1v about every 10 minutes whilst powering the coolbox. When it gets to about 11.6v (only about 2 hours later) it doesn't seem to drop very fast after that - had it on for hours without it dropping any lower.

Although I'm only monitoring that through a cigarette lighter socket gadget.


Thanks again for the help though - it is appreciated.
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