Electrical Problems.

[klatuu]

Well here goes, I would appreciate if anyone can help.

I have a 1984 carvelle, (read early electrics) that used to be a 1.9 WBX I recently converted it to a 2.2 Subaru.

Ever since the conversion the van has been completeley cutting out, when I say cutting out I mean ALL electrcial power goes, the clock does not even tick, after a short period of time everything comes back.

When this initially occurred everything came back in less than a minute, but I have noticed over the past four times it has happened it seems like it has got progressively worse, the second time was about a minute, the third felt longer (3-4 minutes) and yesterday it was about 2 hours.

I would say I can make it happen, initially if i start the van and within 10-15 minutes run somthing high power like flashing the headlights, then it will die (as I found out when i tried to let a car through traffic).
Although yesterday after I got the van back outside the house I flashed the headlights and everything was fine.

It has had a new battery about 8 months ago, I went for the biggest the shop had, 66aH, the alternator Is connected to the live feed of the battery that connects the starter, the permanant live for the subie ECU is connected to this also, the switched live for the subie ECU is connected to the same circuit as the rear lights etc.

Initially I though the there could be too much juice going through the switched circuit, but this should not cause the clock to fail.

Because all electrical power goes, this to me would indicate three things

a) there is no electrical power, indicating the battery is faulty, but when the battery is tested with a multimeter it seems fine.

b) all electrcal power is being sucked up by something else, if this is happenning I would expect something to get hot in the van, nothing feels hot, smokes or melts.

c) there is big short somewhere, but this would cause the battery to drain, get hot, this does not happen.

Other things that I thought may be faulty, Ignition switch, one of the relays, starter motor. but unless anyone has the symptoms of B or C above then these should not stop the clock from ticking.

One other thing that could be hapenning is that there could be a break in the main feed cable from the battery, but if that was the case then the van would not go until it was reparied.

Haviing had a chance to write this down the only thing I can think that it could be is that I have a faulty battery, so I'll hopefully be getting it tested, or replaced, but anysuggestions that someone may have would be gratefully recieved.

[Mocki]

battery connections, and or rotten wire...???

[jammcd649]

poor earth? Either one of the earth straps may need replacing or where it earths to the body is not a good connection, e.g paint/rust etc.

Maybe???

[Fritz]

I have come across something similar in the past, and that turned out to be faulty cell in the battery (I think that was a fairly new one as well).

Change the battery for a known good one , then let us know how you get on.

Regards

Fritz,,,,,,,

[DiscoDave]

One other thing that could be hapenning is that there could be a break in the main feed cable from the battery, .

you may have hit the nail on the head!!!

but if that was the case then the van would not go until it was reparied

but not always!!!

somewhere along the line there is a fault causeing the power to go elsewhere other than where it is needed.
your subie is cutting out becasue the ecu is at some point not getting enough power to manage the engine with out damage so it cuts out, thus killing the engine!

firstly inspect the starter cable, from your description if it is this thats damaged it could be shorting out causing battery to go flat, but if it's starting again after a few minutes it sound more like damage internally to the cable, as it gets hot resistance increases untill it is to high to take any current. as it cools down again resistance is lowered back to where it was and will allow enough current.

as mentioned try a known good battery, check all the connections along the way from battery and starter to alternator, if needed disconnect them, clean them adn put them back.

check alternator burushes if they are worn the will need replacing! what alternator have you got? subies have 90amp i think! make sure it is right.

when your happy with all that, get an ammeter adn when the van is turned off see what power is taken from the battery! should be naff all power to keep memory in ecu and stereo, if it is high, more than about half an amp, you need to dissconnect fuse at a time to see what is using power.

if all is ok, turn it on and measure the amps needed to run the enjine ecu etc to have an idea what current should be used (do this as near to the items as poss) you might have to do this seperately and add up the total!

when you have a result for your engine, go back to the battery and measure the amps again! are they the same or more, if more you'll need to remove fuses on by one to see what is pulling unknown current.

hope fully this will help! remember to set the ammeter at the highest reading before taking measure ment, dissconnect it whilst starting! if it is the starter cable it's size is 35mm2 and if you ahve top replace it you'll be better off with tri rated 35mm cable from electrical wholesalers!

good luck

[klatuu]

Thanks everyone for the help, I have had the battery tested and the ettery is fine there are no dead cells, so I have a bit of searching to do, I'm fairly sure the main earth is ok, but it'll get checked/tested along the way.

i will come back and post when I find the fault.

Thanks again.

[clash460]

One other thing that could be hapenning is that there could be a break in the main feed cable from the battery, .

you may have hit the nail on the head!!!

but if that was the case then the van would not go until it was reparied

but not always!!!

somewhere along the line there is a fault causeing the power to go elsewhere other than where it is needed.
your subie is cutting out becasue the ecu is at some point not getting enough power to manage the engine with out damage so it cuts out, thus killing the engine!

firstly inspect the starter cable, from your description if it is this thats damaged it could be shorting out causing battery to go flat, but if it's starting again after a few minutes it sound more like damage internally to the cable, as it gets hot resistance increases untill it is to high to take any current. as it cools down again resistance is lowered back to where it was and will allow enough current.

as mentioned try a known good battery, check all the connections along the way from battery and starter to alternator, if needed disconnect them, clean them adn put them back.

check alternator burushes if they are worn the will need replacing! what alternator have you got? subies have 90amp i think! make sure it is right.

when your happy with all that, get an ammeter adn when the van is turned off see what power is taken from the battery! should be naff all power to keep memory in ecu and stereo, if it is high, more than about half an amp, you need to dissconnect fuse at a time to see what is using power.

if all is ok, turn it on and measure the amps needed to run the enjine ecu etc to have an idea what current should be used (do this as near to the items as poss) you might have to do this seperately and add up the total!

when you have a result for your engine, go back to the battery and measure the amps again! are they the same or more, if more you'll need to remove fuses on by one to see what is pulling unknown current.

hope fully this will help! remember to set the ammeter at the highest reading before taking measure ment, dissconnect it whilst starting! if it is the starter cable it's size is 35mm2 and if you ahve top replace it you'll be better off with tri rated 35mm cable from electrical wholesalers!

good luck

bloody hell Dave, you been reading a lot of electrical books lately

[klatuu]

well, I've spend the last few hours tracing cables, pulling the dash to bits, poking torches and hands in places that they weren't meant to go.

Inserting relays, testing fuses, bypassing wires, remaking connections, and in the bit where the battery sits the main power cable to the van electrics, (not the cable to the starter) had a taped join, out of curiosity I untaped the join and here it was twisted, TWISTED together .

One of the bits of wire looked ok, the other looked a bit ropey, These wires are a bit big to solder, tidied them up, ran a bit of wet n dry over the external wires, and used a screw connector fitting to join them again, and now everything seems fine, headlights go on, in fact headlights with full beam, hazards, rear heated screen, full speed blower and window wipers and the engine still runs

I suppose the question to ask is would this cause the van to fail?, it does give the symptoms when the van did fail if i disconnect the wires.

So we will see over the next week or so what happens.

[Dan Wood]

That joint probably had a fairly high resistance.

At first, this isn't too much of a problem until you pump more and more current through it.

As the current increases, the voltage dropped by the join will increase, leaving you less voltage for the rest of the van! This is probably why it only seemed to go wrong when you were loading it a fair bit.