1976 MG Midget

[Loren]

In my free time this week, I finished up the front marker light mods. Got everything assembled and working on the bench. Stuck 'em on the car tonight... and something's not right!

The marker light works... but, the turn signal causes THAT light to blink rather than lighting up the other light. I've no idea why that would happen!

I'll have to give it a closer look tomorrow and do some troubleshooting. Musta wired something wrong somewhere.

But, dammit, I'm going to fix that tomorrow. And replace the alternator. And take the damned car for a drive!

Then, I can take the brake system apart, and hope that doesn't take too long to get back together!

[Loren]

Looks like my little 194 LED bulbs don't have an internal resistor. The LED in parallel with the standard bulb won't work because the regular bulb takes all the current. If I disconnect the regular bulb, it works fine!

So, the solution, as much as it annoys me to have to rework a little bit, AND to have to install extra components, is to put a 470 ohm resistor in series with each LED. That should draw some additional current through the LED and get it to work.

Time to experiment.

[Loren]

No, that's not it. Something weird going on with the car wiring.

These cars used "bullet connectors" throughout the wiring harness. They're notorious for getting corroded and causing problems. But, that's not it. I feel like somebody's plugged something in incorrectly somewhere.

Even without the LED's in the system, the RF turn signal is flashing the RUNNING LIGHT. I shouldn't get any turn signal at all with the signal wire unplugged. But, I do. Something is amiss.

Fuck, I thought this car wasn't going to have problems like this! But, I guess anything that's been repainted... somebody unplugged shit, odds are they got something wrong somewhere. Especially since they got overspray on the wires, making it hard to tell what's what.

[Jamie]

Something weird going on with the car wiring.

LBC.... You're not only matching up modern electrical components with old electrical components...those old components are BRITISH.

[Loren]

I'm telling you, it has nothing to do with being British or Lucas.

SOMEBODY PLUGGED SOMETHING IN THE WRONG PLACE.

I just unplugged everything on the LF corner until my parking light finally went out. The wire that's supplying the PARKING LIGHT power is Green/Red. That's a turn signal wire. Power should be coming in on the Red wire. Feels like somebody put this car back together without a wiring diagram, and may have been color blind. They just traced wires and plugged things in until they worked.

Unless somebody's done some splicing (which is possible), I'm guessing they switched things under the dash somewhere. Ugh, I hate crawling under dashboards.

[Loren]

Okay, I think I made some progress. Took a glance under the dash (phone cams are great!) and didn't see anything too much out of place.

Fiddled around some more, and got frustrated that the fuel pump is hot wired to the ignition. No fuse, no connectors (other than a couple wire nuts that I don't want to disturb just yet). So, when I'm testing turn signals, the FP is running. I finally got tired of it and installed the new fuse block. That allowed me to wire in a proper switched fuse for the FP on one of my spare fuse slots. Got that all done... and unplugged the fuel pump! I needed to do the fuse block, anyway. It's surely the cause of a lot of intermittent problems.

With that done, back to the lights. Found a suspect ground. It's the headlight ground, go figure. So, I removed the screw. The bottom of the screw is painted, and the lug on the ground wire is corroded and has a little paint on it. Cleaned all that up, put it back together.

When I first took the left headlight out today (it's the one that appeared to have high/low beam reversed, was working funky), I found that all 3 wires from the headlight were black. Likely an aftermarket plug. But, two of the wires had different insulation than the other. And a quick Google search indicated that the odd wire was the ground. And, of course, it was NOT connected to ground, it was connected to one of the two hot wires.

With that being wired wrong, plus an intermittent ground, I'm surprised that headlight worked at all! I mean, it could have worked on one beam, because there's no polarity. But, when switched to the other... I'm not sure what kind of funky ground loop had to be involved to get that to light up. And, I suspect that could be what was causing the other issues.

I say that, because now things seem to be working properly. At least on the right side. Turn signals, even the LED one, working fine. Parking lights good. Turn signals WITH the lights on, still good. None of the wonkiness that I had last night.

And I got the left headlight plugged in properly, so now it works right.

Just need to put the rest of the left side lights back together and see how they work.

Ugh. This should have been like a 30 minute job, and it's taken all day! But, I guess I'm learning my way around the wiring of the car.

I'm going to order some new bullet connectors and plugs. I should really go around the car and clean those up, and replace what needs replacing. I don't really want to rewire the whole car. But, I can definitely clean up some connections.

[Loren]

After getting my ass kicked by this car all day, at last, success!

Got the headlight reinstalled, and all the left side lights done. Everything works!

Headlights, high beams, running lights (including the new LED ones on the fender), and turn signals (including the new LED ones on the fender).



I've got new solid state flasher modules coming. The hazard flasher was pretty iffy before, now doesn't work at all. The signal flasher works, but I'm hoping a new modern one will have a better flash rate. This one doesn't seem to stay "on" long enough. I just don't like it's vibe.

Of course, that's another rabbit hole that I went down last night. There's the whole "LED ready" flasher thing. But, since I'm still using mostly regular bulbs, that's not an issue yet. No, the weird thing with fully electronic flasher modules is that they are SILENT!

I've caught myself forgetting to turn off a signal at least twice in this car already! It's got a slightly smaller than stock wheel that makes the dashboard indicators hard to see, and I can't hear the flasher clicking over the engine noise.

Today, I learned where the flasher is located. It's behind the glove box all the way on the passenger side. THAT's why I can barely hear it!

When I upgrade the flasher module... it won't make any noise at all. I don't want a buzzer or anything (they do make them), but a proper turn signal clicky sound would be good.

This car uses a 2-wire flasher. Voltage comes in, flashing voltage comes out. Simple. I learned that there are several types of flashers. In particular, there's a 3-wire flasher that has another output to feed a single dashboard indicator (instead of left and right, which would be wired into the regular turn signal circuit). So, I got one of those. I'll send that output to something under the DRIVER's side of the dash to make a noise that I can hear. I'll probably just use a relay and not connect it to a load. That should make a satisfying sound.

So many things to do...

[AScoda]

Extra loud clicky flasher relays exist.

[Loren]

Extra loud clicky flasher relays exist.

They do, but they are pricey. And the ones I found were not LED-ready.

Got the light wiring all wrapped up (temporarily, because I still have to do the relays on the headlights, and will likely clean things up later), replaced the alternator and... took the car for a drive yesterday!

This car is reminding me what it's like to just "go for a drive". There's little joy doing that in a modern car. Everything is too easy, too plush, too fast and powerful. This car, you have to be aware of what you're doing and wring it out a little bit just to keep up with traffic flow! And it's not fast, but the handling is tight and precise and it's FUN to drive, even just around the block.

The closest that a Miata gets to feeling this way is a 1.6 with manual steering. Nothing else newer than about 1982 comes close.

Next up: Gotta fix that brake switch.

[Loren]

Brake switch! Today was the day!

Gave it a really close look. Put a wrench on one of the FIVE fittings, and promptly questioned whether I wanted to disturb it. At a minimum, I'm going to need to buy a 7/16" flare wrench. An 11mm might work, but I only have 10 and 12!

Consulted the MG forum. Found that a lot of people have just bypassed that switch in various ways. The "most correct" way to do it and preserve a completely split braking system would be to remove the whole switch block and replace it with a union for the single rear brake line, and a T for the two front brake lines. But, again... I'm not itching to disturb 46 year old brake fittings if I don't have to.

Another way to go would be to gut the switch block and plug the switch hole with a bolt. Again... I don't wanna fuck with those fittings!

The final option, much simpler, and pretty much where I was already: Remove the switch and plug it with a bolt. Where I'd left it before was to wrap the switch in an absurd amount of teflon tape to keep it from leaking. I like this idea.

As far as keeping separate front/rear brake circuits, it mostly does. There are little tiny o-rings on the shuttle inside the switch block that area seeping slightly, but if one end or the other lost all brake pressure... there would still be SOME pressure in the other circuit. And my hand brake still works dandy. So, I'm cool with it.

As for the function of that switch telling me when I've lost partial brake pressure. Really? I think I'd notice. Earlier iterations of this same car didn't have such warning lights. Earlier still didn't even have split-circuit brakes.

So, I dug around and (amazingly) found a suitable 3/8-24 bolt. It wasn't threaded all the way to the head, so I had to dig up a spacer, which I found. And, most amazingly, I actually found some copper washers! So, I put copper washers above and below the spacer. Blue Loctite on the threads for good measure. And replaced the switch with that. That'll take care of that!

While I was there, the oil pressure switch that "might" be leaking (remember, this is the part that leaked and killed my last Spitfire engine!) is right there. So, I cleaned that area a little bit, and replaced that unit.

That's about it for today. Got a couple things crossed off of the list.

Oh, and I ordered an H4 headlight conversion kit. CHEAP. And it's a genuine Toyota part! Made to convert the FJ40's to modern headlights. So, it's a proper OE glass lens, came with halogen bulbs, came with the ENTIRE WIRING HARNESS! Including fuses and relays! I'm replacing the halogen bulbs with LED so that they won't draw as much juice, and might be even brighter. Will probably wire the low beams as DRL's.

[Loren]

Doing another tech session in da Groj this Saturday (and possibly Sunday if I end up not working). Company is good. Extra hands are good. Working on other people's cars is good. In this case, it would be handy to have someone to work the pedals whilst I bleed brakes and clutch.

[Loren]

Got the brakes bled, and the pedal feels great!

Got the clutch bled, and it was WORSE, so we did it again. Now it's at least as good, maybe a tiny bit better... but, the release point is still near the floor. Will need to find a way to address that. Noticed that the slave cylinder looked old, and the bleeder screw felt loose in the threads when I loosened it. Maybe I'll start by replacing the slave cylinder?

And, of course, I can't touch this car without finding another problem.

Something drained the battery the other day. I charged it back up, but never tried to start it. Took it off charge Friday night, Saturday it's dead again. Got it running with a jump pack, drove it for a bit and now the battery seems to be holding charge enough to easily start the car... for now.

And I noticed that the brake lights have quit working!!! Could those two problems be related? I looked at the wiring diagram... the only things on the same fuse with the brake lights are the turn signals and the horn. Horn wires are dangling loose under the hood... maybe one shorted out and popped the fuse? Will look tomorrow.

And this was my first time under the car. I didn't do a thorough inspection, but I noticed that the transmission mounts are shot. The back of the trans is resting on the trans/frame bracket! So, add new trans mounts to the list. "They" say you have to pull the engine and trans to replace them. But, I found at least one creative person who pulled it off by modifying the removable transmission bracket. I'll probably do that. Might also be able to just fit a different style of rubber mount. (they're just round rubber mounts with studs in them, there are options)

It's always something.

[Loren]

Okay, so I haven't found the battery drain yet, but it's still there. Unrelated to the brake light problem.

The brake light problem is simply a failed brake light switch. But, what a fuckin' rabbit hole!

Let's give that a thread of its own...
viewtopic.php?t=3939

[Loren]

While I'm waiting for my brake light switch to arrive, I figured I'd start planning my "major" electrical system upgrade. Not rewiring the whole car, just updating how things are connected. Adding fuses where there should be fuses, and adding relays to a lot of circuits so that the dash wiring and switches aren't carrying so much current.

If I can get some of this done before I have to install that switch, I won't have to do that temporary hack-job on it and can go right to "final wiring'!

There's a lot to this wiring project, so I started a thread for it:
viewtopic.php?t=3940

[Loren]

Plugging away at mocking up my wiring project. I decided to make a panel that will be supported by 4 rubber feet, and held in place using the mounting points of the OE fuse block so that I don't have to drill a bunch of holes in the car, and I'll have a removable panel that will be easier to work on in the future.

While measuring the available space for that, I noticed that the valve next to the charcoal canister near where I'm working is warm. I found the current leak that's been killing my battery! And it's my fault, of course.

When I replaced the oil pressure sender that was leaking... I ordered a pressure sender for a Midget 1500. Didn't give it a lot of thought. Just tacked it onto an order that I was already making. What I didn't notice is that it's for 77-79. Why is that, you ask? Well, MY car (a 76) has a mechanical oil pressure gauge. It's got a steel tube running all the way up to the dash for the oil pressure gauge.

Well then, what the heck did I replace??? It's an oil pressure SWITCH that controls that valve. They call it an anti-run-on valve. It's switched on to open when the engine is running, off when the engine is off. Helps keep the engine from running on after the key is shut off. The switch is a normally open switch. Closes when there is oil pressure. The oil pressure sending unit works the opposite. It's normally CLOSED to light up your oil light when there's no oil pressure... opens and turns off the light when there is pressure.

So, yeah... the thing was keeping that solenoid valve energized all the time! Weird that it's got power all the time. Maybe that's so when you turn the key all the way off, it still has power to operate until the oil pressure drops. And, of course, it's not fucking fused... which is why I was so confused last night. (I checked at each fuse, and there was no current draw!)

Anyway, glad to have found that problem. Went ahead and ordered the proper oil pressure switch. And I ordered a new set of seatbelts. The old ones look ratty, and don't retract properly.

[Native]

I found the current leak that's been killing my battery!

Whoo-hoo!

And it's my fault, of course.

Lucas is redeemed!

[Loren]

Oh, and I did find that the AR solenoid valve IS fused. It's got an inline fuse just before it. But, it's apparently on an "always on" circuit... that's completely unfused UP TO that point. Genius.

But, I'm pretty close to having all of those problems solved. It LOOKS complicated, but it's really not. Just a matter of pulling connectors off of the OE fuse block, and moving them to different places. Mostly. I'll have to add 3-4 wires just to get converted to a "properly fused and relayed" setup. Mostly just moving stuff, though.

I'll share my first and second draft and my CAD (cardboard aided design) mock-up in the other thread maybe tonight. Once a few more parts arrive and I fab up the panel and pre-wire it all... actually putting it in the car should be fairly easy!

[Loren]

transmission mounts are shot. The back of the trans is resting on the trans/frame bracket!
...
Might also be able to just fit a different style of rubber mount. (they're just round rubber mounts with studs in them, there are options)

Okay, so the stock mounts are just rubber "spool" mounts. About 1.3" diameter and length with 5/16-24 studs on each end. And they're fairly cheap... usually around $6-8 each.

I found on McMaster-Carr, some trick rubber "isolation mounts" that are 1.5" diameter and 1" long with a stud on one end and a threaded insert on the other. That arrangement lets me thread the top into the transmission, without having to worry about not having clearance to fit the bottom stud through a hole. Should make replacing them a snap! I ordered a set of spacers to make up the extra .3", and some SS flange bolts for good measure.

Almost immediately after I placed the order, somebody piped up on the MG forum telling me that I'd ordered the wrong thread pitch! Well, the parts arrived today.

They're the wrong parts (18tpi rather than 24tpi, won't thread into the transmission), but I have to say that compared to any aftermarket engine or transmission mount I've ever seen, the quality is fantastic! And they were only about $9 each. (not counting the spacer and bolt)

So, I'll be returning the wrong parts, and reordering. I'll be out a few bucks in shipping for my error.

The correct size isn't available in the stud/insert layout. Gotta go with insert on both ends. So, I'll need to add a stud on one end and a bolt on the other.

[Loren]

Returned the wrong parts above. Ordered the right parts. Opted to just order some 1" long bolts to fit the mount inserts. I'll cut them to fit on the end that I'm using a bolt. And I'll cut off the head and cut to fit on the end that needs a stud. It'll work.

Made a little progress with the wiring today. Got the brake lights working! And was able to take the car for a little drive. That was nice.

Then, about 20 minute after I got back, there was a little metallic crash in the garage. Went out to look, and the mirror had fallen off of my door!

Midget Side Mirror base.jpg (637.62 KiB) Viewed 6645 times

This is what broke. The hole for the little bitty screw that the mirror pivoted on. Did it's job for 47 years. I could replace the whole mirror for $40-50. But, would it be as good as the original? I think I'm going to clean up the broken part of that casting, drill a larger and deeper hole, and fit a larger and longer screw. I bought a tap and die kit for a reason!

[Loren]

Fixed the mirror. Larger screw. Stainless screw. Should be good for another 47 years. Better than new!

Midget Side Mirror Fixed.jpg (87.54 KiB) Viewed 6641 times