Captain Obvious

I see what you did there.

No problem. I know this is in capable hands. I'll stand back some try to keep quiet.

We talked about it before (I think), but you have to be careful how you apply that formula to incandescent lamps due to the dramatic change in resistance as the filament heats up. For example, I just took a quick measurement off a little 3W inspection lamp bulb and got about six or seven Ohms cold. But for a 3W bulb like that, the resistance SHOULD be 48 Ohms. The trick is that it IS about 48 Ohms WHEN HOT, but at room temp, it's under ten. A couple of those in parallel like the dome light (because the door is open) and maybe the engine inspection lamp, or the map light in the console, or the .... Hope I'm adding value and not muddying the waters.

Steve, Backing up a little (in order to hopefully jump forward?). When you disconnect that four pin connector that goes out to the engine bay (the one with the R, RL, RY, GL wires)... The "short" goes away and the circuit under scrutiny goes OL. And on that connector, you have headlights, front marker lights, and the inspection lamp. All of those things are powered from the W/R wire feeding the fuse block. Either directly, or switched through the headlight switch. Can we please please get a double dog sure that the headlight switch is off?

I'm finding the wiring documentation for the early cars to be lacking and questionable. And not having a 240 here to look at for reference, it's tough. I particularly dislike the way they depicted the fuse block. Took me some time to figure out what (I think) is going on at there. And not showing where the connectors exist on the wiring diagram doesn't help troubleshooting any. And neither does wire colors magically changing along the runs. Anyway, might be old news for you 240 guys, but I came up with this: Note that if you flip the fuse block over and look at the wires colors there, some of them are different than what's shown on the wiring diagrams. I'm assuming the colors shown on the FSM wiring diagram are on the HARNESS side of the fuse block connectors and then didn't bother to list the colors that exist actually inside the block. Most of them line up with the wiring diagram, but some of them do not. Not having a 240 here for verification, I can't add much value. But I'll try to add a little.

Well I don't think I've gotten any wider since the last time you saw me! Haha! So the only thing hotter than the tarmac at that show was inside the big Quonset hut. It was shady, but like baking in an oven. Brutal. Your choice was either bake outside in the sun with a tiny bit of breeze, or bake in the three-sides-closed Quonset hut with no moving air at all. So Birmingham is likely to be like that, but with more humidity, right?

LOL! That was by design. I was looking for shade.

And as Captain Obvious, I'm compelled to point out that resistance readings like what you're taking are dependent on switch positions. By that, I mean... If something like your headlight switch is on, you'll read low resistance from the +12 volt side of the harness to ground, and it's perfectly normal. Same thing goes for the ignition switch. And the inspection lamp, etc. In other words... when you're taking resistance readings between hot and ground, you need to be double dog sure that all the accessories are off and the key is in the OFF position.

Everyone remember just how hot it was out there on the tarmac for the people's choice in Memphis? I went out for lunch with Blue @240260280 and Ms. Blue. We were trying to decide where to go and the answer was "Any place that has air conditioning. Oh... And eat slow!"

Not a very detailed list of which fusible link does what, but this should at least get you started:

And I would recommend that (since this whole thing started with an alternator replacement) you do your first fuse test with the alternator disconnected. Maybe the voltage regulator unplugged as well? If the low amperage fuse (or meter) survives that first step, then plug the voltage regulator in and try it again. And keep working in steps like that?

Steve has this well in hand, but let me just add a couple thoughts... In theory, that's exactly what the fusible link is supposed to do. It's supposed to cook and burn out before the wiring inside the harness cooks and burns out. The copper wire inside the fusible link is smaller than the wiring in the harness and it's intended to fry open before the wires inside the harnesses do. Point is... In theory, if the system was designed properly and fusible link did what it was supposed to do, then, in theory, rest of the wiring "should" be ok. In theory. Second thing is you said "when I attempt to reconnect the battery terminals, I get sparking that definitely does not look normal." - If you have an Ammeter with a 10A range, you could quantify the amount of that current before you get all worked up about the spark. By that, I mean... If you haven't measured the current, you don't really know if it's a problem or not. You could be chasing a non-problem. Maybe (just maybe) the spark WAS just a normal in-rush thing charging all the systems of the car and once that initial hit was gone, it may drop down to the milli-amp or micro-amp range? Connecting an Ammeter in series with the fusible link would give you an idea of how much current you're talking about. Half second ought to be enough for your meter to get a reading?

Haha!! No, not at all. Apparently it was popular with most of the British sports cars up through the sixties? I was thinking that maybe you had one of those in the family that your dad worked on a lot.

https://www.restore-an-old-car.com/positive-ground-cars.html So there.

On final approach now!! Whatever you do... Don't connect the battery until you're sure you've got everything else correct! including the fuel injection power leads. They're both red, so that's an easy way to get screwed up. Ohm them out to the ECU connector if there's any doubt.

Perfect. That means we're doing it right. So to your final question about vacuum bleeding vs. pressure bleeding... Again, I'm no expert on the topic, but I would suggest pressure bleeding over vacuum bleeding for a couple reasons. First, I believe you can generate a whooooole lot higher pressure differential with the master cylinder. I didn't research it, but I would expect that when you push the pedal hard, you can generate hundred(s?) of PSI in the lines. But if you're drawing a vacuum, the max vacuum you can achieve is less than one atmosphere (less than 15 psi). So for pressure bleeding, your pushing fluid through the lines with hundred(s) or PSI, but with vacuum bleeding, your pulling fluid through the lines with less than 15. Seems you would be much more likely to generate that bubble-free "slug" of fast moving fluid if you're using a higher pressure differential. Second, the seals used in the system are designed to keep pressure IN, not keep pressure OUT. All the seals are angled in such a way as to designate which side is the high pressure side and which is the low pressure side. The seals are all designed to expand outward and provide more sealing force when the pressure behind them increases. I've run the exact same scenario that Zed Head did (bleeding a clutch slave cylinder) and when I released the slave plunger, it pulled air past the seal back into the fluid side. So either he got lucky, or I got unlucky, but what worked for him did not work for me. I had to pressure bleed because the vacuum generated when I released the slave plunger allowed air in faster than it would pull fresh fluid from the clutch master.

Well I never spend huge amounts of time working on something, that in the end, is really unnecessary. Ever.

Haha!!! I'll get right on that! Or not.

I don't think it would be much different. That's what I meant about the fluid flowing fast coming out of the master cylinder. The reason it would flow so quickly through the lines is because of the small volume that actually exists inside the brake lines. Grannyknot's put it well above, but let's put some numbers on it... If the ID of the lines is .118 inches (3mm), then the cross sectional area of said tube is .011 square inches. That means in a ten foot run of brake line, there is only about 1.3 cubic inches of brake fluid. I'm thinking that even if there is a bubble in the middle somewhere, it's just going to get pushed out ahead of the next slug of liquid when you're bleeding the system.

Haha! What about the "None of us need more work to do." part?

Good pic. As for the fluid dynamics... I had one class in fluid flow and thermodynamics*. I consider it the worst class I took in my entire educational career, and I got zero out of it. At the time I had absolutely no interest and (as an EE) could see absolutely no practical value to me. So it bounced off my brain and I managed to scrape through with a "C" using short term memory and a stiff grading curve (because pretty much everyone tanked the tests). But now... Now that I've got a whole bunch of automotive related applications, I bet I would get a whole lot more out of it. *Probably told this story before, but I'm gonna do it again anyway.

Richard McDonel, I believe your asking "Why wouldn't air bubbles get trapped inside the hard line or rubber lines since they are higher than the bleeder screw on the wheel cylinder?" I'm no fluid flow expert, but I'm thinking the fluid coming out of the master cylinder flows so fast that it pushes virtually a full slug of brake fluid liquid along inside the small diameter lines. The slug of fluid doesn't really want to separate and it just pushes all the air out ahead of "the wave", and even when you lift the pedal to get ready for another push, even if a bubble were to flow out of the wheel cylinder, it won't happen fast. You'll blow that bubble out on the next push. Capillary action and vacuum lock and all that... That's my non expert theory anyway.

I agree with Patcon's assessment above, but since I love a list... Here are my answers to your questions. 1. How much difference? Immeasurably small. 2. How hard would it be? Pain in the butt to do it right. 3. What size? Doesn't matter. Glad we could talk you out of it!

I think ZH nailed it about drilling out the rivets. If you're absolutely insistent on running a stock regulator (guts included), then I think that would be your only option. There's no way the electronics would do well in the plating process and you would have to remove them first. I guess maybe, just maybe... There might be a company who specializes in this sort of thing where they would pot the sensitive bits in some sort of compound to prevent the plating fluids from making contact where you don't want them. But I think it would be easier to drill the rivets out and desolder the guts to remove them. Not "easy" at all, but probably "easier". If it was a matter of life-n-death, I could also picture some sort of sealed dam walls being glued/sealed to the base to build a wall around the guts. Some creative walling and partial submersion to just the right depth might work too. But there's no way I would want to hand a part like that to someone else and ask them to plate it. It would have to be you doing it yourself with a home kit.