Board logo

battery/loom problem?
jabbahutt - 31/8/07 at 07:01 PM

Evening all

Could really do with some help here. I fitted a battery 4 days ago to attempt to start up the engine for the first time. Things conspired against us and the attempt was abandoned.

Went in the garage tonight to have a second crack at it and the battery was completely flat, not even enough to light a dash bulb!!

Before leaving the garage after the first attempt I removed the ignition key, disconnected the ignition switch. Apart from the positive battery lead to the starter and the negative to chassis earth non of the loom was connected

So what did I do wrong, I suspect it was me rather than a faulty battery but have no idea what i did wrong.

Tonight I've done the same but isolated the negative of the battery as well.

What would be the most likely causes for the problem? what did I overlook and do wrong?

All the loom connection that are loose at the moment have tape over the ends or insulated female spades etc.

Would really like some peace of mind as don't really fancy disconnecting the negative for the rest of my life

I'm a complete idiot with electrics so any explainations please make as easy to grasp as possible.

Many thanks, maybe have better luck tomorrow, sorry the loom is a vicki green one

Nigel

[Edited on 31/8/07 by jabbahutt]

[Edited on 31/8/07 by jabbahutt]


jabbahutt - 31/8/07 at 07:10 PM

really panicing now, just read a thread that went on about fried coils if it's a points based dizzy which mines is

please put my mind at rest that even though I didn't leave the ignition on and disconnected the switch I haven't somehow knacked up my electrics!

plus what did I do wrong i thought I'd done everything needed

thanks


David Jenkins - 31/8/07 at 07:25 PM

It's all down to systematically isolating things until you've identified which bit is causing the problem.

Do you have a multimeter? If so, put it on its highest current setting (10 Amps or higher), disconnect the battery, and put the meter leads between the battery terminal and its recently removed lead (it's safest to do this with the negative/chassis lead, as accidental shorts to chassis won't matter).

With the ignition off you shouldn't see any current flowing. If you do, pull all the fuses out and try again. If you STILL see current flowing, you have a problem! If you don't see current flowing, put the fuses back in one at a time until you see current flowing again. Take out all the other fuses apart from the last one you put in (just to be sure). That is the circuit with a problem.

When you've identified which circuit is faulty, disconnect everything on that circuit (pull all the plugs off). Reconnect things one at a time until the current flows again.

Until you've sorted it out, I suggest that you recharge the battery then leave the negative lead off, to avoid any problems and/or undue wear and tear on the battery.

HTH,
David


adithorp - 31/8/07 at 07:43 PM

The only other question mark if Davids sugestions don't work: Whats the batteries history? Is it new or old. Modern batteries do tend to just suddenly fail with no warning signs. Especially if they've been standing unused and then put back into use.

adrian


jabbahutt - 31/8/07 at 08:12 PM

uh oh I'm stumped. As explained earlier 95% of car electrics aren't connected including fuse box etc

Looking at the wiring diagram I wrongly assumed that if I wanted to test start the engine i'd just need to connect ignition switch, coil and starter.

Just been out to garage and with negative lead disconnected, ignition off and also disconnected there is a 3.5amp reading on meter:0

so what have i done? what is likely to be drawing 3.5a of current and have I broken anything.

I appreciate that it's difficult to diagnose without seeing but I don't understand what is taking the current.

I take it I'm correct that leaving the negative off the battery it's impossible to flatten the battery?
thanks for the help.

brand new battery fitted tonight after found last one completely jinxed after 4 days!!

[Edited on 31/8/07 by jabbahutt]


adithorp - 31/8/07 at 08:19 PM

take the fuses out one at a time untill the current drops and thats your leaking circuit.

Is the alternator connected?

adrian


jabbahutt - 31/8/07 at 08:24 PM

alternator is connected to loom, as is the starter motor but the are no fuses wired up. engine and gearbox are earthed

would an alternator draw current? have i completely screwed up before really starting and ruined a piece of electrical kit?

I was always going to have problems with the electrics, this is just the beginning!!!


[Edited on 31/8/07 by jabbahutt]

[Edited on 31/8/07 by jabbahutt]


adithorp - 31/8/07 at 08:29 PM

It can draw current if its either wired wrong or duff. Disconnect it and see what happens.

adrian


jabbahutt - 31/8/07 at 08:31 PM

it's brand new, could I of damaged it?


adithorp - 31/8/07 at 08:48 PM

possibly but it could just be faulty.

adrian


jabbahutt - 31/8/07 at 08:53 PM

well some progress. disconnected large brown wire and current draw dropped to 0.02A
disconnected smaller wires which connect to pins in plug recess and current read 0A

Is there any way to check if the alternator is faulty? I bought it from a company over the internet

I connected the wires as per a diagram i found on here.

thanks for the help it's much appreciated. Any further pointers welcome it's a nippon Denso Micra alternator


jabbahutt - 31/8/07 at 09:01 PM

things looking up

found these in a post and delving deep into old posts

The Vicky Green loom uses Brown as the unswitched live and Green as the switched live. White is the ignition live.

I have a Vicky Green Loom and a Nippon Denso alternator. The problem is that the field coils of the alt are permenantly connected to the battery (thin brown wire). I had to modify my loom to use a switched live feed.

means nothing to me but it looks like my problem. now just need to know how to rectify it.