Electrics suddenly cutting out while driving!

[rosss]

slightly Terrifying...!
the electrics on my bongo have just suddenly started cutting out while I'm driving. I'll be driving along the motorway with the radio on etc... when suddenly the radio goes off, the milometer goes nuts, the van sometimes jolts (changes up a gear i think) - the glowplugs light comes on... and so does the roof one sometimes i think... - all lasts about half a second then it all goes back to normal and is ok.

Here's a few things i have been fiddling with recently...
* I cleaned the fuel filter.
* I fiddled around in the banjo filter hole unable to find/get a banjo filter.( i don't think i left anything in there.)
* while i was doing the above the driver door was open and it was raining... later when i drove i realised (duh) that the door was all soaked through and the electric window on that side wasn't working. The window started working again later but electrics inside got pretty wet i guess.
* and finally i have a parasitic battery drain (which i think is caused by the starter motor) - which i've temporarily resolved by removing the negative cable from the battery whenever i'm parked up. I've just been slipping it off and on (not too tight) - which i at first assumed was the cause of these cut-outs... however i tightened it up before my drive today and it seems to be on there pretty firmly but it still started happening...

Any clues appreciated!

[nth]

and finally i have a parasitic battery drain (which i think is caused by the starter motor) - which i've temporarily resolved by removing the negative cable from the battery whenever i'm parked up.

Don't think in 20 odd years of working on cars I have ever seen a starter motor causing a parasitic drain on a battery? How much of a a drain is there?
Are you getting a good charging voltage at the battery? Might be worth leaving a voltmeter connected to see whats happening to the voltage when the fault occurs.
I would also have a look at the main earth connections between the engine, chassis & battery.

[Ian]

Check that the main 100 amp fuse is not loose. It's under the bonnet inside the plastic housing near the main vehicle battery. It should be firmly bolted in place from underneath.

[rosss]

Don't think in 20 odd years of working on cars I have ever seen a starter motor causing a parasitic drain on a battery? How much of a a drain is there?
Are you getting a good charging voltage at the battery? Might be worth leaving a voltmeter connected to see whats happening to the voltage when the fault occurs.
I would also have a look at the main earth connections between the engine, chassis & battery.

Thanks! ha, that's interesting and what a few other people have said to me too..
Here's a thread about the drain... it was between 0.5 and 0.9 amps - wasn't consistent. If i removed the starter battery cable then there was no drain...
viewtopic.php?f=3&t=75898&p=704067&hili ... ic#p704067

I'm going to look at those main connections now...

[rosss]

Are you getting a good charging voltage at the battery?

The battery is only a few months old. It's reading 13.96 volts with the engine idling (less than 1000 revs)...

[g8dhe]

If the -ve terminal is being constantly undone and put back I would suspect the intermittent loss of power could well be down to that!
Likewise its very unlikely that a starter motor is going to be a parasitic drain, the contactors have to be operated by a relay from the ignition switch. Much more likely might be a damaged alternator regulator or diode pack, if you have excluded anything else added to the vehicle, have you measured the current being drawn ?

Have you looked in the contactor tube to see if anything is amiss yet ? When you say you have removed the starter motor connections do you mean the whole terminal arm or just simply the starter cable itself ?

[rosss]

Didn't i read there was a recall on bongo's, something about the drivers window switch if it became wet, you say you left it open and it stopped working... maybe worth looking into as it may have caused damage further back somewhere

Oh boy! yeah it got really wet inside. (Has started working fine again though.)
Thanks -
here's the related thread.
viewtopic.php?t=74869
I've emailed enquiries@mazdainformationcentre.co.uk to check if mine was one of the ones recalled.

What are people's thoughts on the potential danger of this? I'm supposed to be driving to Ireland tomorrow - 6-7 hours...
The thing is that i'd been slipping the negative cable on and off for ages... it was the drive immediately after the window thing that this first happened on...

[rosss]

I just phoned up my local Mazda dealers and gave them the VIN number and they said there was no outstanding recall on it... so i guess that's fine re window switch fire then i guess...

[g8dhe]

The thing is that i'd been slipping the negative cable on and off for ages...

I hate to say this but that is the problem Stop leaving it till later, sort it now.
Have you looked at the suggestions in the other thread, the current isn't down to the starter, it will be one of the other un-switched circuits that come directly off the battery or via the 100 Amp fuse. There are lots of possibilities so its a case of remove fuses in turn and measure the current in each circuit till you pin down the culprit.

[rosss]

I hate to say this but that is the problem

Hi Geoff... thanks for all your help! Actually that's great... easier fix hopefully.

I've really cleaned and tightened up the terminal connections... so hopefully that'll stop the intermittent electrics cutting out... i'll take it for a test this evening.

as for the drain...

it will be one of the other un-switched circuits that come directly off the battery or via the 100 Amp fuse.

I removed the entire cable from the +ve terminal that leads to the 100 Amp fuse etc and the drain was still there. I'm sure the drain occurs only when the Starter Motor Cable is connected to the battery... (Before i worked that out i removed all the fuses including the 100 Amp one one at a time and nothing made a difference.)

so that leaves the "other un-switched circuits that come directly off the battery."
is there a diagram here somewhere that shows what else is connected to that circuit? Is the alternator on the same circuit?

There's a thing added under the dash that changes the colour of the dash lighting and let's you dim/brighten the dash lights... maybe that's on the starter motor circuit somehow...

Have you looked in the contactor tube to see if anything is amiss yet ? When you say you have removed the starter motor connections do you mean the whole terminal arm or just simply the starter cable itself ?

Ummm... i haven't actually taken the starter motor out... is the contactor tube in there?

thanks again!

[g8dhe]

I gave a Youtube link to replacing the contactors on the original thread.
When you say "I removed the entire cable from the +ve terminal that leads to the 100 Amp fuse" I'm not sure what you mean ?
The +ve terminal has a solid bar (not a cable) leading to the the 4 fuses, which includes the 100 Amp fuse;

the Glowplug fusibile link is attached by bolt to that bar;

the starter motor feed also comes from that bar;

Do you have any pictures you can post of the +ve terminal connections, I'm wondering if there might be some other non-standard feed connected ? Do you have a Leisure battery or anything else ? The illuminated dials power feed would normally be connected after the Ignition switch, otherwise it would stay illuminated with the Ignition off!

[rosss]

Yes sorry that's what i meant, i removed that entire bar and the fusible link cable... so that all that was left attached to the positive was the Starter Motor Cable.
I'll triple check it now and take a photo...

[rosss]

So with the lead that's attached to the +ve in this photo it shows the drain...

https://www.dropbox.com/s/ycf8pqlryx4v5 ... y.JPG?dl=0

anywhere between 0.2 and 1 amp once it's settled... not sure what that depends on - maybe how recently i've been driving (was 1 amp last night and now it's 0.2)

without that lead attached in the photo - with just the bar that goes to the 100 Amp etc and the fusible link - it shows no drain...

[g8dhe]

OK, that would suggest that the Starter motor or the Contactors are the drain, but as I said previously not a common type of fault, I can only think you may have some debris hanging around the contactor contacts, which means removing the starter and opening up the contactors see the video https://www.youtube.com/watch?v=5pnySma88gY

[g8dhe]

Just a thought - you aren't a Northern Japan Cold Start set up with dual batteries are you ? Check on the nearside is there a heavy duty cable intended to connect to the +ve of a second battery hanging around ?
If so that terminal is LIVE direct to the first starter battery!!! Its normally well insulated if its disconnected for any reason as there is NO fusing at all and quite capable of delivering a full 500-1000 Amps under a short circuit ......