Alternator/charging

[ryza]

Hi guys dont post very often but am really stuck with this one and would be great if someone could help me out or give advice. The problem is my car will not charge and cannot find the problem, on the last 3 trackdays ive had 3 new alternators and all seem to go wrong, will explain. I done a trackday this saturday and i done a few laps and i noticed the battery light flickering as i revved the engine a couple of times and though maybe belt slipping. Came in checked the belt was fine. Went back out was ok for a couple of laps, battery light starts flickering on and of then it just stays on and boom no power steering. So thought well ill try another alternator got a brand new one from jayar put it on, worked done not even half a lap battery light flicking on and off then stays on so now it seems this one is dead!! The alternator is earthed ok, the connection has battery 12v checked alsorts of things, could anyone give me any ideas or help to what may cause this? The only thing it could be is wiring but if it was surely i wouldnt get 12v at the alternator? Thanks

[saxova]

Check the starter motor wiring - my bolt came loose and caused my battery to keep going flat.

Also sand all the O ring connectors for a better connection!

[AlexFocusST]

As above ,
check that all all main power cables , alternator , starter motor , battery connections are tightened and make sure all earth wiring is rust free clen and screwed tightly.

[ryza]

Must the cables to and from the starter? All earths have been sanded etc, my battery is in the boot and earthed in the boot but it should still be a good earth. Really annoying only got 5 laps in through the whole day thanks guys will give it a try if anyone else has had any problem like this it would be helpful to have your feedback!

[axsaxoman]

sounds more like the small connecotr on the altrnator not having a good connection as htis is what comntrols the alternator charging ,so if its internmittant connection that could turn your power steering on + off .
the later type with the plastic push on connector were most problems early type with 8mm nut didn,t have these problems
yes the main alternator wire goes ot starter as the other lead should be a direct connection to the battery .
you have moved battery to insdie car ,so all connectors on this lead MUST be soldered ,not clamped or you will get voltage drops due to extra legnth of cable ,unless off course you have hydraulic actuated cable end fitting tool.
just screwing in the screws onthe battery connectors will never give a permanent good connection on battery cable ,same goes for large size earth leads either buy ready made ones or solder the ends on

[AlexFocusST]

Have you got an earth wire going from the boot to the front , or have you just earthed it to the chassis in the boot???

[ryza]

I thought the small wire was just a wire to light up the batteryon your dash when it detects its no charging so even if that was of shouldnt it still charge? I tried having the car running and connected the live on the alternator to a battery next to the car and earthing the battery back to the alternator and did not charge it surely if there is 12v at the alternator and then you have it spinning shouldnt it charge the battery or is this completely wrong? Thanks

[106maxi]

You need to fit the alternator light.
I lost 3 races this year due to alternator problems, all because the alt light wasn't fitted.
I've knackered 2 alternators as a result.
Fit the light and see how you get on.

[ryza]

What do you mean i need to fit the light? You mean the battery light on the dash i have that fitted cant work out why its not charging or its destroying alternators

[axsaxoman]

the circuit for the light isenergising the alternator field windings so it won,t function correctly without that circuit being correct

[ryza]

Right so tonight we tested some alternators and we found out my cars destroyed 3 alternators 2 new ones and a old one! Got one on there that works and is working fine now. What i need to know if anyone could help is if the small wire that goes to the battery light was connecting and disconnecting at occasions then really quickly at times as it seemed loose at the engine plug would this cause the alternator to mess up? I cant see why it would but i could be wrong as axsaxoman said that needs to be right to energise all the coils for it to kick in once its kicked in you can disconnect it and it runs by itself anyone got any ideas/experienc with this sort of thing? Thanks

[axsaxoman]

yes if it did as you suggest it would cause voltage spikes and that would take out the regulator pack inside the alternator .
make the plug connection a goodfit or change it
maybe solder a wire to the pin in the alternaotr and cut off the plug on the loom and make a connection to the soldered on fly lead from alternator.
or use old type alternator with bolt on wire

[ryza]

I have a good connection on that wire into the loom now so i need to try it now and give the car a thrashing to see if it does it again. I will have the alternators tested and see what is going wrong. What we done was have the live on the alternator going to a battery and earth the alternator to the battery then we connected the small connector on alternator to the live on the battery and spun the pulley with a fast electric drill and the ones that worked put out 14.57 volts and the ones that didnt really pulled the drill down on power and dropped voltage to 12.3 so does that sound like regulator has got got a problem? Thanks gmc you've been a great help pointing me in the right directions!

[106maxi]

Yes.
I melted the rectifier in mine too!

[ryza]

Ahh okay its kinda good to hear someone else who's had the same sort of problem haha! What part is the rectifier? I no the regulator and brushes are easy to get to and change which is quite handy