Pre Cat Alternator dying??

[Wildfire]

Since the demise of my alternator at my first Growl, the alternator hasn't quite been the same. With my headlights on (35W HIDs) and the blower, my output drops to 11V.

Now this could be 2 things:

1. I disturbed wires whilst taking the dash off.

2. The alternator is dying or the wrong one.

What was fitted as standard to the Pre Cats?

Where can I get another one?

Will it be expensive?

Could it be anything else?

Cheers

Chris

[spend]

Does it behave well when the blower is off? They can be electrically troublesome when they get seized or those (speed) resistor packs failing?

[Wildfire]

With everything off it runs at just above 12V, then lights on 12V, blowers on it drops to 11V and a bit further with the mains on (also HIDs).

I have a feeling the RAC only replaced it with a 45 or 65 amp alternator. I have been quoted £140 for a brand new (not recon) 100 amp alternator.

I'm due to drive to Devon in 2 weeks and would like to know the electrics will be ok.

[L1OFF]

Wildfire said:

With everything off it runs at just above 12V, then lights on 12V, blowers on it drops to 11V and a bit further with the mains on (also HIDs).

I have a feeling the RAC only replaced it with a 45 or 65 amp alternator. I have been quoted £140 for a brand new (not recon) 100 amp alternator.

I'm due to drive to Devon in 2 weeks and would like to know the electrics will be ok.

I paid £70 for my replacement from a LR spares place on the net, I will look for the reciept when I get home and let you know the name. I also got the old one repaired by a small car elctrics shop (£30 for a replacement rectifier pack)that's the normal failure reason.
Alan

[spend]

Early ones were only 65/70A IIRC.

[Wildfire]

Hmmmmm.... could just be the gauge as I was fiddling behind the dash a while ago.

What's the best way to check the output to the battery?

Where else could I be losing power?

I'm a bit of an electrical numpty.

[L1OFF]

The pre cat uses a A127/65A from a Disco 1 (Paddock Spares)
Make sure it the correct "hand"
Alan

[spend]

You can spin them around (60 degs) if desperate. We all use a nut behind the tapped hole anyway..

There was a chap on ebay that sold Lucas rebuild kits that weren't expensive, and on a bench its pretty straightforward swapping major component clusters?

Whats with the fuse question (maybe Ant has told you already they don't have one )

[LordGrover]

Wildfire said:

I'm due to drive to Devon in 2 weeks and would like to know the electrics will be ok.

If you get a problem on the way make a note of Dulford's telephone number: click. You're bound to pass them on the way...

[sunwharf]

Does the charge warning light come on when the egine is running and does it come on when you switch on the ignition before starting the engine? 11 volts would indicate your battery is discharging (duff alternator likely) or you have a dodgy earth (high resistance). You might be able to have the alternator repaired by a local electrical engineer if it just needs new Diodes.

Nick

[Barkychoc]

If you want to know how to take it to bits here you go, this was a bling exercise but its on a pre serp alternator.

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Also have you considered that it could be a poor earth giving you issues?

[Barreti]

Here are a couple of old threads about precat alternators which might have the info you need Wildfire
clicky

[Wildfire]

Barkychoc said:

Also have you considered that it could be a poor earth giving you issues?

Hmmmm... no, not considered that one. Were's the best places to look. Will I have to spend all of tomorrow under the car removing and cleaning up all the earth straps?


The charging light never actually went out after the RAC guy changed it. But then I may have blown something behind the dash when the last one went.

I'm not going for a week or so and it's only a 10 min job to change the alternator.

Maybe I'll have a look at as many earth straps as I can tomorrow, after my geo setup, then order a new one if nothign gets better. Mind you the charging light thing is still annoying.

Can someone give me a numpty guide to checking all the outputs/resistances/amperages with a multimeter?

Cheers

Chris

[spend]

Wildfire said:

The charging light never actually went out after the RAC guy changed it.

Sure he put the wire on the correct terminal, could just be connected to earth. Otherwise the alt is faulty or wrong one..

Pull the wire off the alt (brown/green or something on a spade - not big browns or little black anyway) and the light should go out, touch it to ground ad the light comes on. All with the ign on will tell you if the light / dash is all OK.

[Wildfire]

As Hoov said, I think it's probably the wrong alternator, but I'll try that tomorrow.
Cheers

Chris