silvertop zetec alternator problems

[mikebishop]

Hi, just after some advice,

Went out in the tiger Sunday morning, hoping to get to the Tetbury show, we were early so carried on to the Kemble airfield for a coffee, had the coffee, went to get back in the car and it wouldn't start, the engine turned over once the died and the electric fuel pump started to splutter.

luckerly I found a very helpful man with some jump leads who helped me to get the car started, we connected the batteries and that was enough to get the car started,

We drove home to Yate no problems, well no problems until we got passed Didmarton, where I noticed that all the dials and the lights were not working, then I noticed that the indicators were not working either Managed to get home just as it started to splutter. I turned the engine off opened the garage went to restart it to put it onto the garage but it was dead flat, didn't even turn over and no lights or fuel pump.

I started to charge the battery with a trickle charger, then I tested the battery 30 mins later, A neighbour helped we with a multi meter, it had about 11V on its own, we then tried to test the alternator but the car would start, engine turned over once then died, I managed jump start the car from my miss car, we then tested the battery again while the car was running and it was still about 11V (meter was quite hard to read) the meter didn't change when I revved the car to 3-4000 steady.

Am I right in thinking that the alternator is not working?

The Tiger has a 2.0 Silvertop Zetec with weber throttle bodies and a fast cam.

What are my options on alternators? standard ford replacement or are there other options?

The alternator is located under the throttle bodies on the drivers side of the engine.

[mikebishop]

FYI, the battery was new in April.

[Facial Hair Optional]

That's pretty much near as dammit what happened to mine Mike. Sounds like the alternator is not charging the battery. Don't assume that the alternator is knackered though, as I said in my text, mine was just a loose wire in the back of the alterator under the plastic cover. Tightened it up and it's been perfect ever since.

A lot cheaper (free!!!) than a new alternator mate too! They can vibrate loose those wires on high revving kit cars I find. I would check inside the rear cover (if it has one like mine did) before splashing out Mike, you are gonna probably have to take the alternator off either way dude!

[Moleman]

My alternator bolts always work their way loose so if you are lucky it could just be that so I would check if the belt is still tight enough before buying a new one. 

[Facial Hair Optional]

Colin is right, I'lve had my alternator bolts come loose, my water pump pulley and an engine mount bolt completely come off before now! It pays to do a bolt down check every once in a while.

[Iancider]

Mike,

If the alternator stops charging you ought to see the ignition light on on you dash.  Of course if the bulb is gone that would be a problem.  When an alternator fails it is generally one of a few things.  The outer or stator winding needs a small current through it to produce the magnetic field.  If the skinny wire to the alternator is loose (White brown if it is a proper loom) then it will not charge.  The big terminal (Brown) might also be loose.  Earthing is via the body so it is pretty unlikely that it will not be earthed BUT check that the engine earth braid is still connected and not chafed through or broken.  (Usually bare woven or insulated Black fat cable).  The alternator can be serviced.  Under the rear cover you can gain access to the slip-ring brushes.  When they wear down they spark until all contact is lost.  If you cant see brush above the top of the holders then they have worn too short.  A simple replacement with the alternator on the bench - about £6 last time I did this..  The rectifier ring or pack may also fail and that used to be a spares item but I have not replaced one in years.  Generally rectifiers only go if the alternator has been short-circuited.

Also last but not least - slipping fan-belt?

['The Gaffer']

All good advice there as usual, let us know what the problem was

[Facial Hair Optional]

Hey Mike, any news on this issue mate? Did you get to the bottom of it? Have had major car woes myself this last week, I'll tell you all when I next see you. All looks ok now though (I hope!)

[Brandy Barrel]

The difference between an alternator and Dynamo is that there is a bunch of electronics in the alternator, these components need a voltage to be able to work, as they switch the charge on and off. That's why you you can't bump start a flat car with an alternator.
The light is a battery light which can work in both directions depending on the differential voltage. I won't go into the light not going on or not as I can go on for ages.
I think your battery has gone down, if you put it on charge it should have reached over 12v.
If you do an overnight charge then take it too one of those true and battery people they can check it with a device that will check the the overall capacity and performance, which you can't do with a basic voltmeter.
However before you do that, you can do a basic check, install the battery in the car after a full charge, now put your voltmeter on positive supply and negative earth, if the voltage reads over 12.4v then it's charged, start the car and switch everything on, lights fan etc etc, the voltage should now lift to 13.5v as the alternator kicks in and replaces the drain.
As a higher voltage output from the alternator is required to charge. This is the key indicator the alternator is working. If you see the voltage dropping when everything on, then alternator is not working.
But before you do anything else check continuity on all your wires, that means take both ends of the wire off and check the resistance to make sure no breaks, zero or very low resistance means ok. Then check all connections to terminals are tight and made good.