Bad day on the LUCAS 3AW Warning Light Control Unit production line?

AL on the alternator IS powered with the ignition off, so there is my real problem. It looks like the tab for AL is bolted on to the post for the B+ connector.

This just came back from a clutch replacement, so engine was out and in, and somehow the alternator got smoked after re-install, so it was sent out for a rebuild … so the notion that it was reassembled wrong in not out of the question.

Well damn! Just looked at other pictures of alternators, and they reassembled mine incorrectly. THe tab does not go on the B+ post - there is a separate AL post I see that was not used. I think this fault was on the alternator rebuild shop.

Looks like someone connected the AL wire to the B post. There are number of variations to the connection locations on the AC11 Lucas alternator, but here is a photo of the back of my 1969 alternator.

As you can see, AL is not where you’ve connected it.

I do not know if its the correct unit for 68, but this after I rebuilt it as it was.Looks like A3W gizmo tab at top.

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Yep, exactly. Thanks. Now that I know what to look for, the post is clearly marked AL and is different from the B+ where the tab was attached. I have moved the tab. The ohmmeter now reads very high resistance between the battery leads, which means it’s not draining the battery. Pictures I see show some sort of insulator, shielding the alternator from the tab, beyond just the insulating washer. I’ll fabricate something to replace what is missing.

Next job: cooling fans run as soon as ignition is switched on. I unplugged a wire leading to the Otter switch, and they still run. So I’m guessing they are mis-wired, because the wiring diagram does not show any relay in there.

That insulator is unobtainium. I epoxied my pieces, and its goofy shaped.

Maybe a short piece of teflon tubing?
You don’t want either post to touch the case.

In case it helps here is the back of the alternator on my Feb 1968 FHC. Pretty sure this is the original wiring but I did have the alternator rebuilt 20+ years ago.

68 E-type FHC

Sounds like you don’t have the correct wiring diagram for you 1969 Series 2. There is a radiator fan relay (2 if you have A/C) located on the picture frame. BR wire in the diagram below goes to the Otter Switch. The relay is a 3 terminal type where W2 and C2 share a common terminal.
If your fan is on all the time with the ignition it sounds like it has been rewired at some point.

Corollary- There are 10 types of people in the world; those that understand binary and those who don’t.


What are the extra nuts on the manifold?

Not my car (and I own a Series III) but I believe those secure the alternator shield

Yep it on Bigbirds car the spacers appear to be on theoutside

Spacers go under the heat shield. They are just staged there.

Ok plus 20

Wow, that’s pretty.

Where is the cooling fan relay physically located? There are two relays behind the battery, but one is labeled ‘Alternator’, and the wire colors on the other are all wrong (plus it is a 4-wire relay, not 3 wire as the diagram suggests). Wire colors on the Otter switch and the fan motors are all correct, so I’m thinking I’m just looking at the wrong relay.

As I said on my post yesterday, it/they (if you have AC) are located on the picture frame. Here’s a photo:

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Brilliant - thanks. A while ago, someone pointed behind the battery and told me one of those was the radiator relay, so I was convinced I knew where to look :slight_smile:

Doesn’t help that I thought ‘picture frame’ was the tag next to the battery with the car numbers on it.

Phffft - a rookie mistake that doesn’t EVEN make my Top Twenty

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