In France - Bongo not starting

[eoptio]

Hi

thanks for the suggestions. Had a good look at all the wiring and the glow plug rails. Removed the bracket with the vacuum pipes to have a look behind that, removed the cables going over the cyclinder head, removed the glo plug relay and the battery negative that is connected next to it. I can't see any wire damage/touching anywhere. It may be that the temp fuse blew as the wire we used for the temp fix was not thick enough for the temp fix? The weather is not improving so I'll leave it as is for now, at least we can get started and going, so should be able to make it back to the UK ok.

Thanks for your help all

K

[g8dhe]

then connected the wire directly wthout a fuse, started first time, disconected wire immediately as started to smoke. Engine kept running albeit lumpy, letting it run now to warm up a bit. So the fusible link seems to be the problem, if a 30 amp fusse blows immediatley would that suggest there is a problem further on in the glow plug circuit wiring? Cannot find anything obvious nor find the glow plug rail touching any metal anywhere? Or could it just be the 30 amp fuse/wiring used was not enough? What to look for next?

The fuse is NOT THE PROBLEM, it is trying to protect you from a serious fire! If you short out the fuse, then either the wiring will burn up or the Relay will burn out next - if either of those happen then you will be really stuck! My guess would be a shorting glow bar bus that's quite common, after that possibly a glow plug itself might be at fault but that isn't very common at all.

The fact that you managed to start would suggest that the problem is towards the last glow plug on the bar, but its not an accurate way of trying to identify the location of the short circuit!

[eoptio]

Hi

yes realise there must be a problem somewhere, just can't see anything not right on the glowplug rails. Will have another look, weather has now cleared up a bit, just to confirm what I am looking for: the bar should not touch anything but the glowplugs

thanks

K

[roofraisers]

Yes , that basically sums it up.
You did touch on one other point though. The wire you are using as a temp. fix does need to be fairly thick. Note how thick the wires are that feed the glow plugs & compare it to the size of yours. If the temp. wire is too thin it won't be able to carry the large amount of current that the glow plugs require safely & will overheat.
You can get around this by having several lengths of your (maybe thinner) wire with the ends joind together. This will make a thicker wire.This will allow more current to be carried safely. If the wire doesn't get as hot when you try and start the bongo, try the fuse again. The trick here is to make the temp. wire at least as thick as the other Mazda glow plug feed wire.

You seem sure, that there is no obvious shorting points, but me mindful of a burning smell when starting the Bongo.
Your nose may lead you in the right direction of the fault.

Safe trip home.

Nigel

[westonwarrior]

If you cant find the problem ie the short, its probaly a plug as stated.

To get you going or home, you can hold the wires together and start it then remove the wire this will at least keep you going or use easy start until you can get it to a specialist to check the glowplugs

I don't like or advise either but needs must and all that, just dont bodge it and leave a wire attached all the time as the glow plugs go on and off for some time when starting from cold and you could risk a nasty fire.

[eoptio]

Hi

good tip ref using several strand of wire. The wire I have used as a temp fix is thinner than the glowplug wire, but it's all I have at the moment, will make one out of a few strands. I have checked the glowplug rail and all the wiring I can get to from above, inluding everything near the battery, can't find any issues with it. Just to get home I'll use the temp wire to start, then remove it as to not make it overheat, it will run lumpy until warmed up but at least it should start and hopefully get us back to the UK for a proper fix

Thanks all

K

[bigdaddycain]

I wouldn't worry too much about the lumpiness and smoke, the smoke is unburnt fuel and will clear when up to temp and had a run...

[eoptio]

Hi

we made it back to the UK with no further problems, thanks to all for suggestions/advice. Now looking to fix this, does anyone know what amperage the fusible link should be and where I can get one, Mazda?

thanks

K

[g8dhe]

Not noticed anyone on the forum saying they have replaced the fusible link, a couple have replaced it with fuses 30 Amp in one report. But it might be worth trying Mazda first. Glad you got back OK !

[westonwarrior]

you can get them from a mazda dealer you will need the vin code

[eoptio]

Hi

had another look at this today. As I could not find a fault in the wiring or a short on the glowplug rail, had a look at the glowplugs themselves. Removed each glowplug and tested each indivudually with a spare battery, all seemed to work ok. When connecting two plugs to the rail, the 30A fuse did not blow, as soon as connecting 3 or more plugs (irrespective which ones) a 30A fuse would blow. I guess this suggests the glowplugs draw more than 30A when all connected, I'll see if I can find a some higher rated fuses tomorrow. In teh menatime doers anyone any idea how much they sghould draw, I have read somewhere 17A each, others seem to have wired in a 30A fuse that seems to work ok?

Thanks

K

[missfixit70]

Pretty sure the fusible link is 30amps, as already stated I think, upping the fuse is NOT the answer (as Ithink has already been said), it is that value for a reason, I'd suggest new glowplugs or checking thoroughly the wiring is not touching to earth unless you want to risk you & your passengers lives with a serious vehicle fire. The fault is not the fuse, it is blowing for a reason. Check the resistance of the glowplugs, can't remember the value offhand, I'm sure a search will reveal the specified values if someone doesn't consult their manual in the meantime.

[missfixit70]

these may be of interest
http://www.igmaynard.co.uk/bongo/forum/ ... ce#p380747
http://www.igmaynard.co.uk/bongo/forum/ ... ce#p486608
http://www.igmaynard.co.uk/bongo/forum/ ... ce#p438977

[eoptio]

Hi

thanks for reply, yes would not put in a higher fuse if the fusible link was 30A, thanks for confirming. One of the links refers to a resistance of 0.5 ohms per plug, I was getting more like 2.0 ohms on each glowplug. Would that explain it, ie new glowplugs?

Thanks

K

[teenmal]

Hi

had another look at this today. As I could not find a fault in the wiring or a short on the glowplug rail, had a look at the glowplugs themselves. Removed each glowplug and tested each indivudually with a spare battery, all seemed to work ok. When connecting two plugs to the rail, the 30A fuse did not blow, as soon as connecting 3 or more plugs (irrespective which ones) a 30A fuse would blow. I guess this suggests the glowplugs draw more than 30A when all connected, I'll see if I can find a some higher rated fuses tomorrow. In teh menatime doers anyone any idea how much they sghould draw, I have read somewhere 17A each, others seem to have wired in a 30A fuse that seems to work ok?

Thanks

K

Hi,
This is a generalisation.

Listed below are some guidelines to refer to when checking fast glow plug systems.


48 amps - all glow plugs are operating correctly.
36 amps - one glow plug is defective.
24 amps - two glow plugs are defective.
12 amps - three glow plugs are defective.
0 amp - all glow plugs are defective
.

For slow glow systems use the following amp rating to test:


36 amps - all glow plugs are operating correctly.
27 amps - one glow plug is defective.
18 amps - two glow plugs are defective.
9 amps - three glow plugs are defective.
0 amp - all glow plugs are defective.


The above specifications are applicable to four-cylinder applications.
If you have more than four glow plugs, just add 12 amps
for each fast glow plug
add 9 amps for each additional slow glow plug.
NOTE: Depending on outside temperature, you may
experience a surge of current up to 140 amps.

Cheers..