electrical advice needed..

[LittlestHobo]

Right, somehow i've shorted the wiring on my bus (turns out that in indonesia where I bought the van red must be negative and black positive, either that or soemthing really freaky happenned)

So my visible damage is melted wires coming from the alternator (think its the laternator).

Is there likely to be any other damage?

Do I need to replace the whole wiring loom? can i get away with tracing back the wires just replacing the parts that havel melted and using a junction box?

Cheers
Simon

 

[bambam]

I would be amazed if red was earth many years ago some cars were wired with the chassis possitive but you should have noticed the pos on the battery would have been connected to the chassis wire.... I dont think that would be your problem i would have thought you wiring loom would have shorted to earth causing the melting if you follow the loom you may find the short the alternator wire is earth from ign warning light until engine running then becomes live ... did you fit alt,,, how for has wiring burnt, have you been running van for long ,

 

[ZedBed]

Black is +ve on all buses. Brown is earth. Sort of opposite of house wiring. If you're not thinking it's easy to go wrong. That's how I fried a customers elec ignition. An expensive few seconds for me!

 

[LittlestHobo]

Thanks guys, here is a pic of how the battery was wired up before I bough/imported t it, when it arrived in the country it didn't have a bat so I wired the red plus the other wire to +, and black to -.

The van didn't run, chust chugged on the key, then created alot of smoke and melting plastic, the alaternator leads are now bare, and they appear to have melted some of the wires a bit further back that were wrapped with these wires (I'll get a pic later)

So what can i get away with safely doing to fix the problem?!

Cheers guys
Simon

 

[bambam]

daft question is the earth lead connected to the starter if not when you crank it the engine will try to earth any wire it can and melting as a result

 

[LittlestHobo]

I think the starter motor earth is ok I will double check though... (though I had to google where the starter motor is - incase you havent gathered this is all new to me...)

there was a wire loose at the front of the engine below the fly wheel, blue one, it may have come loose from my fiddling though....

Now this is a daft question, I am trying to raise the vehicle at the back so I can trace back and replace the wiring if possible...Is it ok to put the axel stands on the chassis cross beam towards the rear of the bus (but before the rear wheels)?? If not where is the best place to but them? For some reason the back axel bit doesn't look quite like it wants to take an axel stand...

Thanks for your help..

PS it looks like it is the red lead from the alternator that is completly melted and burnt out, although it does appear to have damaged some of the other ones as well...

 

[krusty]

Could the red cable thats on the alternator and runs to the battery be shorting out on the alternator casing?
I had a similar thing on my truck.

The cable that went from the alternator to the battery was touching the outer casing and melted a lot of cables.

Might be worth checking that its only attached to the actual bolt that comes out of the alternator.

 

[Sparky]

Thanks guys, here is a pic of how the battery was wired up before I bough/imported t it, when it arrived in the country it didn't have a bat so I wired the red plus the other wire to +, and black to -.

The van didn't run, chust chugged on the key, then created alot of smoke and melting plastic, the alaternator leads are now bare, and they appear to have melted some of the wires a bit further back that were wrapped with these wires (I'll get a pic later)

So what can i get away with safely doing to fix the problem?!

Cheers guys
Simon

Ummm. Air con! What luxury.

Can't help much with your description of what's gone wrong, where are you? Someone local may be able to help, or you could pop round to theirs and see how a bus should be wired up.

Just a thought.

Sparky.

 

[LittlestHobo]

Cheers Sparky with that name I thought you were going to be my saviour!

Yeah the aircon, not really needed, I'll probably take it out at some point when I know a bit more to be honest...

Based in hampshire if anyone is near southampton.

I'd like to try and have a go at it myself if possible, I'm looking to install a leisure battery at some point so what I learn now can only help...

here's a pic of the frazzle...bare copper wire goes at leats ast far back as past the back wheel (this is as far as I've got) it also seems to trunk off here as well and heads across to the other side of the van from a differnt loom...

Bugger

 

[Sparky]

Hmmm well yes I should be able to help, I'm not too far from you to be honest (was brought up in Hythe and Rownhams) so if you do get stuck help is at hand. The wiring diagrams on Vintage Bus are very useful.

You say it heads over to the other side? I've not seen this on any bus I've worked on. This may be the problem, perhaps someone has already put a split charge system in and the terminals are resting on the chassis?

Sparky (I try to be more helpful in future).

 

[LittlestHobo]

Thanks Sparky, very decent of you..im actually in winchester...ill do some more digging around and let you know what i find....seen the samba wire diagrams thanks...im about to order some wire length....anything special i should order?

beers, food or even cash happily available for any help...

thanks

 

[LittlestHobo]

Looks like the damage isn't as bad as first thought...after some more digging it turns out the red burnt out alternator lead doubled back and ended up at the starter motor, so the burn out is limited from the alternator to the starter motor (don't know what its done to either of these yet) so rather than a rewire I just need to cut out the old, add a junction box here and there and replace the frazzled wires hopefully...(sound like a good idea?)

I am still a bit confused as to how this happenned though I must say.

When I attached the black lead to the neg terminal it did spark quite alot. Does this mean it was on the wrong battery terminal?

Also there appreared to a be a loose blue wire (though may be from my fiddling after the event) below the alternator...would this have caused an issue?

How do I connect the battery in the future? (god that sounds so dumb!!)

Cheers

 

[Sparky]

Glad the damage isn't too great.

Should be no need to add any junction boxes just a new wire from the Alternator to the starter motor. The wiring diagrams show 6mm, i don't know which alternator you have but 6mm is just on the small side as it's only rated to 50A (your alternator could be 55A or 75A).

There should be a blue wire from the alternator and heading off to the front of your bus (it runs the generator light).

Don't forget your bus is different to the wiring diagrams due to the alternator being fitted. The diagrams show the dynamo feeding a regulator. On your bus the output of the alternator is equivalent of the output from the regulator.

As for which is +ve on your bus it's the one that goes from the starter motor to the battery (should be, but you never know what's been done before)

Have you damaged anything else? Who knows! get the wiring sorted crank it over and see what happens. If it cranks over the starter's OK, if the charge light goes out and there's about 14V on the battery the alternator's fine. Not much else really.

Hope I got all that right if not someone will be along soon to put me right.

Sparky.

 

[LittlestHobo]

Cheers Sparky, some of the frazzle melted other wire coatings as well so I'll need to replace them, hence the junction box...

Hopefully I'll get things running at the weekend...

 

[ZedBed]

Before you refit the battery, if you have a meter set it to ohms and measure between the +ve battery lead and earth. If you get a reading there is a short to earth somewhere.

Not a silly question. Connect + lead first then -ve. This way if your spanner clonks some metal while you're tightening the the +ve, you won't get sparks. I don't think you can have connected the battery the wrong way round - the battery post terminals are different sizes to prevent this.

 

[LittlestHobo]

Thanks for the advice guys....right I've replaced the burnt out wires, turns out only two needed replacing.

I have found a lead that comes out of the back of the distributor cap its about 8" in length, is covered in like a string cover and appears to have nothing to plug into.

Any ideas?

 

[bambam]

there are only two things the distributer needs one is a feed back from the coil the other goes to a suppressor if the wire connects to the points it goes to the coil it sounds about the correct lengh

 

[LittlestHobo]

Hi Thanks for that have some pics which may help... there are already wires that go to the coil..the one on the back of the distributor cap doesn't fit

The green lead is the homeless lead in question...

Plus another close up, also the black wire connected at the bottom of the picture, what is it? (is it in the right place?)

Below is the wiring into the coil (i think)

Thanks for any help!!

 

[67panel]

thats the oil presure switch,the green wire goes to the negitive side of the coil.make sure the ign live feed is on positive side and feed to carb choke and cut of valve come of pos as well,should be a black wire but as your wiring has been messed with could be anythink :roll:

 

[LittlestHobo]

sorry, another plonka question....the oil preassure switch, should it have a lead plugged into it right? (it looks like it)...the manual should be here by wednesday...

im kiind if thinking that the lead at the.back.of the distributor cap maybe left over from movving the coil for that darned aircon...r