billkent22

Hello, im in desperate need of some help.

Ive got an old mk3 fiesta done 50k miles on a '95 plate only had it a few days.
Ive had problems with the battery dying, i put a new battery on and this dyed too, i checked the charge rate and im getting 9.5v at the battery...rubbish!

Before i buy a new alternator i want to check the wiring because i suspect its not right however i cant get my head round it!

This is the starter motor, small red wire going to the bottom post is ignition, that must be right as it turns over (when its got enough juice) the thick red one goes straight to the battery.




The other post (which has a braided wire going from it to the body of the starter) had the one wire from the alternator attached to it, not sure thats right!?

martysmartie

iTrader: (1)

It doesn't look right no, in respect of that wire going to ground.

Does your battery light illuminate with the ignition on?

Martin

cabriolet

only if you are trying to charge the starter motor the lead from the alternator should be on the top terminal so it goes back to the battery

mothrs2k

the small wire from the alternator should go to a 1pin plug somewhere down near the crossmember, this is your battery warning light which is essential otherwise your alternator wont charge the battery. the braided wire from starter body to solenoid is right. there should be a thick red from alternator to starter motor, then a thick red from starter motor to battery + terminal. try that out

billkent22

Excellent, ive got this wiring right now however....even with a new alternator its still not bloody charging
I have checked the continuity of the thicker red wire from the alternator to the starter, all o.k.
I have my doubts about the condition of the thin blue wire and now you mention it wont charge without this i reckon its my problem. I have used a test light and it lights up on the small part from the alternator so i know this is alright.
My question is should it light up if i touch the test light on the other part of the wire i.e the bit that disappears up behind the O/S headlight and into the car?! Because i get nothing at all.

martysmartie

iTrader: (1)

Which is why I first asked you an important question, which you still have not answered!

Suspicion is always placed on the alternator when it's not that to be at fault.

So does your warning light work?

No your light won't illuminate if you are grounding it on the wire with the ignition on, it will though if you ground it, whilst connected to the wire.

It will charge irrespective, if revved hard enough.

Martin

cabriolet

blue wire .green death. these wires go green inside and die or as said joint beneath the radiator

martysmartie

iTrader: (1)

Plenty of Fords have this exact same setup (and probably others), it's perfectly normal, the battery is connected to the starter anyway, therefore they are interconnected.

Martin

GVK.

Continuity checks on battery cables are almost useless.

You need to do volt drop test on the circuit when all connected.

http://www.fluke.com/fluke/usen/comm...sevoltdrop.htm

You can have continuity on just one strand of the battery cable but it will break down under load.