My alternator..........again!

[peaktorque]

I have been trying to get my head around my alternator wiring, I've already asked this question in another forum, but as it is Wedge related it would cause any harm asking here either........

(copied from E+D)
The alternator in my TVR (350i) isn't the correct one for the car (it came free with the engine).

It is a Lucas LRA407 (AFCL) from a Range Rover, no other info on it and the terminals are not marked. There is plenty of info on Lucas ACR units but not this.

I have it wired in a manner of which it charges/regulates 14v, but it is not right as it gets warm and drains the battery when the car is switched off. I also can't connect the battery/exciter lead as one of the two live cables connects to it.

The alternator has two main terminals one bigger than the other. On the correct alternator for the car (Lucas A133-65) the two main wires connect together on the main fat terminal and the exciter on the small terminal. I also have a link wire from one of the main cables with a spade connector on the end which I have no reference to but there is a matching spare terminal on the alt. which it fits. If I wire it up this way the charging light stays on and no charging at all.

The only way to get it charging is to put one of the main wires on the small post and the other onto the larger, the separate spade terminal also has to be connected. No other combination of wiring will work.

What am I doing wrong? Or am I flogging a dead horse and should just get the right alternator for the car?
(I can't see why it couldn't be made to work, but it's doing my very small brain in!)

---

Does anyone have further info on the correct alternator for an'85 350i? The bible isn't really telling me all I need to know. Does anyone else have the extra wire with a spade connector on the end linked to one of the main brown live wires?

Thanks

[adam quantrill]

Yes! I've used an alternator like this. In fact it might be in the 350i now. Gone dark, so I'll try taking some piccies in the morn.

I have had reasonable success using later alternators on wedges, for instance the later SDi ones, just seemed to be a matter of splicing the mating plug into the loom and bob's yer uncle.

[peaktorque]

Got a bit more info:


I removed the alternator and took the plastic cover off of the back and found the terminals marked on the voltage regulator, which are S, B+, IND, D-

I have a permanent live to both S and B+, IND goes to my dash light and D- is the surpressor.

The only way I can get it to charge is to link S to B+ with a fly lead. The dash light stays on if they are not bridged.

I'm thinking that it is wired right but there is a fault within the alternator?

[adam quantrill]

Well for what it's worth, this is my one:

[peaktorque]

Thanks Adam, looks similar to mine:-



Big wires to the larger post, small wire to the slimmer post, spade connector (linked to thick cables) to flat connection and skinny wire (at the top) to suppressor. I have to link the IND terminal to permanent live to get it to charge (and the dash light off)

What is job the orange wire for on yours?

Thanks

James

[adam quantrill]

The orange wire goes to the suppressor cap.

[Wedg1e]

From my hazy memory, I was under the impression that the IND connection should be wired to the dash warning lamp. This then supplies the initial juice via the lamp to the field windings. Once the alternator is spinning the voltage generated causes the lamp to go out.
It's probable that the way you have it connected is causing the permament drain.
Ransack the internerd for alternator wiring explanations, there are a few

[peaktorque]

Wedg1e said:

From my hazy memory, I was under the impression that the IND connection should be wired to the dash warning lamp. This then supplies the initial juice via the lamp to the field windings. Once the alternator is spinning the voltage generated causes the lamp to go out.
It's probable that the way you have it connected is causing the permament drain.
Ransack the internerd for alternator wiring explanations, there are a few

Pretty sure that it correctly wired now.

This IND circuit seems to be the suspect, I need to have a switched live for this via the light and currently despite the dash light working I don't have any power there.

Thanks

[adam quantrill]

Ahh yes, you can't keep the field windings permanently connected.

As a temporary workaround find a switched live under the engine bay and tee off that.

[peaktorque]

Two crocodile clips and a bit of wire are doing the job at the moment

I have 2V to the IND terminal with the ignition on, no V with ignition off. This I believe to be correct.

The regulator is faulty I suspect.

One week to get a new regulator!


Taking the old shed to Le Mans

[Barkychoc]

This is in the Haynes 1970-1992 V8 Range Rover Manual.
I don't know if it applies.
(Its in the supplement at the back)

[peaktorque]

Barkychoc said:

This is in the Haynes 1970-1992 V8 Range Rover Manual.
I don't know if it applies.
(Its in the supplement at the back)

Thanks, quite handy that manual as there is some useable info in there.

The wiring is correct on mine as it turns out, but the regulator seems to be faulty (despite regulating the current fine when running!)

[adam quantrill]

If you have discharge problems (oohh err Rev!!) when parked up you could just disconnect the earth lead to the battery when you stop.

I had a fault that affected the charge circuit once - turned out that something behind the dash had shorted out, I think maybe one of the meters was going wrong, possibly the lighting for one of them. I would try a search but these days it's almost pointless with the 2-year limit.