Leisure Battery Draining

Technical questions and answers about the Mazda Bongo

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stevlor
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Leisure Battery Draining

Post by stevlor » Mon Mar 12, 2018 2:33 pm

Hi guys,

A while ago I fitted a split charge relay kit and so my leisure battery powers internal lights, radio/cd player, cigarette sockets and also (apparently) the door mechanism for the sliding door. Thing is when it last came back from the garage the coil light kept flashing on the dashboard (garage says nothing to do with them...) I looked it up and it said it was often due to low charge, and lo and behold if I haven't driven it for a few days the leisure battery is used up, no internal lights etc. So something is draining it all the time (I checked all doors are closed etc). What should I check? I know the looms in the doors can be a problem sometimes, but what should I do to check them?

Thanks in advance.
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g8dhe
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Re: Leisure Battery Draining

Post by g8dhe » Mon Mar 12, 2018 4:45 pm

A Split Charge Relay only handles the charging of the battery from the Alternator, have you also fitted a swap loom ? Or how is everything else connected to the leisure battery ?

Check the TWO charge fuses one in each lead from each battery going to the Relay, often one of them will blow if the LB is allowed to get very low, in which case ALWAYS REPLACE BOTH fuses as the other will be damaged.
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Bob
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Re: Leisure Battery Draining

Post by Bob » Mon Mar 12, 2018 5:18 pm

When the garage says, "Nothing to do with us", did they fit the split charge system, have they done work on it, or have you just asked them to fix it and they refused?
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Re: Leisure Battery Draining

Post by wonkanoby » Mon Mar 12, 2018 10:29 pm

what radio is in this
stevlor
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Re: Leisure Battery Draining

Post by stevlor » Tue Mar 13, 2018 2:32 pm

g8dhe wrote: Mon Mar 12, 2018 4:45 pm A Split Charge Relay only handles the charging of the battery from the Alternator, have you also fitted a swap loom ? Or how is everything else connected to the leisure battery ?

Check the TWO charge fuses one in each lead from each battery going to the Relay, often one of them will blow if the LB is allowed to get very low, in which case ALWAYS REPLACE BOTH fuses as the other will be damaged.
I fitted the swap loom that came with the charge relay. The leisure battery still charges while I drive as it has a bit of power left for a while after a long drive - does that mean the fuses are currently ok?
stevlor
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Re: Leisure Battery Draining

Post by stevlor » Tue Mar 13, 2018 2:34 pm

Bob wrote: Mon Mar 12, 2018 5:18 pm When the garage says, "Nothing to do with us", did they fit the split charge system, have they done work on it, or have you just asked them to fix it and they refused?
Sorry should have been clearer, they were just checking over the bongo, not the LB and they hadn't been involved with the installation either. It's just the problems with the flashing coil light and battery drain only started after I picked it up from them!
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Re: Leisure Battery Draining

Post by g8dhe » Tue Mar 13, 2018 5:47 pm

The feed for the swap loom fuses - Does it come directly from the LB +ve terminal or is it fed from the relay side of the charge fuse to the LB, some swap looms make the mistake of using the charge fuse to protect the cable to the swap loom fuses, it means that when the LB charge fuse blows it causes confusion as to what is happening as power is also fed from the SB via the relay itself when the engine is running, which makes it all seem fine, when in actual fact the LB never sees any charge and the swap loom is being fed from the alternator/SB when the relay is operated. Then when the engine is switched OFF there is no power to the swap loom and hence the ECU error light when starting.
If this is not the way its wired and the Swap loom fuses are fed direct from the battery then it may mean the battery is no longer holding charge, or as you originally surmised there is a drain, in which case you need to put a multimeter in circuit to measure the drain BUT only do so when the engine is OFF the charge current is likely to blow the fuse in the meter otherwise! With the meter in circuit you can then measure the drain and remove each fuse in turn to which circuit has the load on it.
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