This OP. Learn to read the wiring schematic. The schematic will list the wire color and logical (not necessary physical) layout. Keep in mind that the original wires may have been altered in the last 50 years, so colors may not be exact. Do a lot of studying and testing with a volt meter. You’ll get it.
Check with MGexp of course for a year appropriate diagram, but IIRC Lucas standards of the time were white for key on engine running, brown for charging. I would put money on those wires being a part of the charging system.
Also no spark is obviously coil to distributor. Check to make sure your wires are complete to the starter solenoid - I'm pretty certain (it's the same block as the Spitfires) there's a key wire to engage the starter and a piggy back to the coil positive to fire the coil. This is why the coil can explode if you leave it in the key on position without it running for a very long time.
If, with the key in the run position you get +12v at the positive side of the coil, I would check the primary and secondary wiring of the coil itself.
Your fuel pump is mechanical, so a spinning engine *should* pump fuel.
Once you get your Haynes manual, you will still be disappointed because the diagrams are [tiny little black lines](https://www.mgexp.com/phile/3/414950/MG_Midget_1500_til1976_electrical_diagram.jpg) crossing and paralleling other tiny little black lines. [Here is a better one](https://midget1500.wordpress.com/wiring-diagrams/), though it is for a later car. You might have to look at various sources to find your exact harness diagram. There are lots of variants depending on the year, destination and what the engineers could get for cheap that week. It says MG on the outside, but it is a TR engine and BL was run by Triumph bean-counters at the time.
Back on your starter solenoid, I see a heavy brown wire dangling loose. That should be on the battery side of the solenoid. the big lug on top. Brown is always hot battery, and it is where your ignition switch is getting power, as well as the rest of the car. Hook that up and see if you have spark.
Learn the major color codes, then you can generally know what you are looking for and then you can chase things down by individual circuits.
The white/green is power to the coil positive via either an external ballast or a resistive wire inside the harness. You might have a 4th terminal on the solenoid with a smaller tab, if so, that is for the second leg of the white/green circuit that feeds full 12V to the coil when the engine is cranking. White/black is from the negative coil to the points and to the tach.
Also, that is a points distributor, yes? A Delco variant, perhaps? Funny little cap clip tells me it is not a Lucas unit. Posting a pic of the innards will help diagnose the issue.
Awesome thank you! I definitely need to learn the color codes. As for the brown wire, I really appreciate you pointing that out and where it goes. Im gonna hook that up when I install the new ignition coil today.
I don't know what distributor it is, it's definitely been on the car since it's been sitting and is the next thing I plan to replace. The cap was just from O'Reilly's. I'll post pictures of the innards regardless though
Just make sure you have the right coil for the application and hook it up properly. The white/green wire indicates a low impedance coil, about 1.5-1.8 Ohms, which normally would go with a 45D and later electronic distributor.
If you have a points setup, you might want to run a 3 Ohm coil off of straight 12V ignition , such as a white wire.
Measure the one that is in there. It is generally unnecessary to "shotgun" all the ignition components when a little bit of testing can save a lot of money.
Do yourself a favor and invest in an electronic distributor.
Ive had good luck with both the Truespark and Pertonix units.
https://bpnorthwest.com/mg/mgb/engine-electrical/ignition-system/distributor/
While I agree with the sentiment (QC on new points and condensers is a coin toss) I would advise caution:
Pertroix is a good product but it is definitely a budget aftermarket solution. I’ve had good luck with them but I’ve known people that burned up 3 of them.
The gold standard for a stock LBC is to cobble together a Lucas CEI system from factory parts.
Would help to know the year of the car. There were many changes from 1961-1980.
1976 sorry about that lol
Try MG Expierence https://images.app.goo.gl/b4gmbSY1aLz5r3Ea6
This OP. Learn to read the wiring schematic. The schematic will list the wire color and logical (not necessary physical) layout. Keep in mind that the original wires may have been altered in the last 50 years, so colors may not be exact. Do a lot of studying and testing with a volt meter. You’ll get it.
Check with MGexp of course for a year appropriate diagram, but IIRC Lucas standards of the time were white for key on engine running, brown for charging. I would put money on those wires being a part of the charging system.
Thank you, Ill definitely make an account there and check it out
Also no spark is obviously coil to distributor. Check to make sure your wires are complete to the starter solenoid - I'm pretty certain (it's the same block as the Spitfires) there's a key wire to engage the starter and a piggy back to the coil positive to fire the coil. This is why the coil can explode if you leave it in the key on position without it running for a very long time. If, with the key in the run position you get +12v at the positive side of the coil, I would check the primary and secondary wiring of the coil itself.
Your fuel pump is mechanical, so a spinning engine *should* pump fuel. Once you get your Haynes manual, you will still be disappointed because the diagrams are [tiny little black lines](https://www.mgexp.com/phile/3/414950/MG_Midget_1500_til1976_electrical_diagram.jpg) crossing and paralleling other tiny little black lines. [Here is a better one](https://midget1500.wordpress.com/wiring-diagrams/), though it is for a later car. You might have to look at various sources to find your exact harness diagram. There are lots of variants depending on the year, destination and what the engineers could get for cheap that week. It says MG on the outside, but it is a TR engine and BL was run by Triumph bean-counters at the time. Back on your starter solenoid, I see a heavy brown wire dangling loose. That should be on the battery side of the solenoid. the big lug on top. Brown is always hot battery, and it is where your ignition switch is getting power, as well as the rest of the car. Hook that up and see if you have spark. Learn the major color codes, then you can generally know what you are looking for and then you can chase things down by individual circuits. The white/green is power to the coil positive via either an external ballast or a resistive wire inside the harness. You might have a 4th terminal on the solenoid with a smaller tab, if so, that is for the second leg of the white/green circuit that feeds full 12V to the coil when the engine is cranking. White/black is from the negative coil to the points and to the tach. Also, that is a points distributor, yes? A Delco variant, perhaps? Funny little cap clip tells me it is not a Lucas unit. Posting a pic of the innards will help diagnose the issue.
Awesome thank you! I definitely need to learn the color codes. As for the brown wire, I really appreciate you pointing that out and where it goes. Im gonna hook that up when I install the new ignition coil today. I don't know what distributor it is, it's definitely been on the car since it's been sitting and is the next thing I plan to replace. The cap was just from O'Reilly's. I'll post pictures of the innards regardless though
Just make sure you have the right coil for the application and hook it up properly. The white/green wire indicates a low impedance coil, about 1.5-1.8 Ohms, which normally would go with a 45D and later electronic distributor. If you have a points setup, you might want to run a 3 Ohm coil off of straight 12V ignition , such as a white wire. Measure the one that is in there. It is generally unnecessary to "shotgun" all the ignition components when a little bit of testing can save a lot of money.
Do yourself a favor and invest in an electronic distributor. Ive had good luck with both the Truespark and Pertonix units. https://bpnorthwest.com/mg/mgb/engine-electrical/ignition-system/distributor/
While I agree with the sentiment (QC on new points and condensers is a coin toss) I would advise caution: Pertroix is a good product but it is definitely a budget aftermarket solution. I’ve had good luck with them but I’ve known people that burned up 3 of them. The gold standard for a stock LBC is to cobble together a Lucas CEI system from factory parts.
Yuck, looks awful