Mg midget wiring diagram

Anyone have a pdfof them? I have an amalgamation of many years and sources in my bay to exercise the demons from. Sso im not sure what years i need, cause I'm not sure what yearsparts are from. 

Try advanceautowire.com

They have good diagrams when I need them for MGB. 

Each car is like a page at most, so they have multiple years in the same pdf and it makes it easyish to flip between years and "what should be"

The  majority of wiring is the same for the B or the Midget of a given year. So if you can't find Midget specific at advanced autowire, use the B version.

I replaced the harness in my bugeye (that has a 1275 from a 73) with a new one from https://www.britishwiring.com/ a few years ago. I am also running an alternator. I put it in a car that had a hacked to bits old and crusty harness that had been powering some ford engine that had been swaped in and removed way before my ownership, so I spent the time with a diagram figuring it out from scratch.

I got good information from  https://www.mgexp.com/ and https://www.ahexp.com/ that helped. There are significant differences year to year, so I would say get the one for the year of your chassis and go from there.  you should be able to find a PDF of one somewhere on MGexp.

If its engine related, I might be able to help as they are all pretty similar. What's troubling you?  (I also have a haynes manual and a few other platform specific books for reference)

I will say though, at this point if it is a patched original, just get a new one from the first link. its really money well spent. 

You have PM, I found a PDF of a full workshop manual for the Bugeye sprite. Its from back in the day and its 230 pages of black and white, but might prove useful. 

Aren't most Lucas-based wiring diagrams fairly standardized in terms of things like wire colours? 

AHA, BAM 

http://www.spritespot.com/Downloads/Workshop%20Manual/Nc%20Wiring%20Diagrams.pdf

This and other useful stuff from http://www.spritespot.com/referencedesk.htm

Also, for supreme headache savings, get a laminated color version here https://www.ebay.com/itm/MG-Midget-1972-1973-US-Spec-COLOR-Wiring-Diagram-11x17-/220366787043?pt=Motors_Manuals_Literature&vxp=mtr&hash=item334ee251e3&campid=5336904795&toolid=10001&customid=lgqxop3qzl001iil00004

Ah, and here is a full workshop manual 

http://www.spridgetguru.com/AKD4021_12thEd.html

(I found where I stashed my repository of useful links)

Apexcarver said:

Also, for supreme headache savings, get a laminated color version here https://www.ebay.com/itm/MG-Midget-1972-1973-US-Spec-COLOR-Wiring-Diagram-11x17-/220366787043?pt=Motors_Manuals_Literature&vxp=mtr&hash=item334ee251e3&campid=5336904795&toolid=10001&customid=lgqxop3qzl001iil00004

I swear you could put the wiring diagram for my Land Rover on a business card.

Keith Tanner said:

Apexcarver said:

Also, for supreme headache savings, get a laminated color version here https://www.ebay.com/itm/MG-Midget-1972-1973-US-Spec-COLOR-Wiring-Diagram-11x17-/220366787043?pt=Motors_Manuals_Literature&vxp=mtr&hash=item334ee251e3&campid=5336904795&toolid=10001&customid=lgqxop3qzl001iil00004

I swear you could put the wiring diagram for my Land Rover on a business card.

Pretty much ditto for the bugeye, but the later spridgets have a bit more to them. 

Thanks y'all!

Its a buddy of mines car that he bought a reproduction harness for and began install. He quit when he found that wiring is not his forte, and british is a bit different than the chevelles hes used to. 

Its theoretically a 67, but i know when i was messing with British stuff in the 90s that title years often didn't match components, and that everything seems to be swapped around. I know this one has a datsun five speed, who knows what else. He got it this way.

I really appreciate the resources and help yall! Its been 20+ years since i touched lucas stuff.....

Keith Tanner said:

Aren't most Lucas-based wiring diagrams fairly standardized in terms of things like wire colours? 

Yes. Lucas does this really well despite all the jokes. Here are the main codes:

• Black - ground -
• Brown - always on, unfused +
• Purple - always on, fused +
• White - switched, unfused +
• Green - switched, fused +
• Red - parking lights +
• Blue - headlights + 

These assume negative ground. For positive ground (usually pre 1967) the colors are the same but polarity is opposite. 
 

After the main colors, Lucas then uses tracers. Blue with red is low beam headlights, blue with white is high beams. Another example is horns, which are usually two-wire with a switched ground. The + side of the horn is purple (always on, fused). The - side is purple with black where the black represents a switch that grounds the circuit. 
 

I can go on but it's probably time for someone to chime in with a Prince of Darkness joke. 

In reply to Carl Heideman :

Please go on! The most informative thing ive seen all day.

In reply to Dusterbd13-michael :

The ones above are pretty universal. It starts to get more model specific after that, but the main colors still give a lot of information. 
 

For example, the left turn signals are usually green/red and the rights are green/white. Since they're both green, you know they're switched from the key and fused. 

Another example is the coil. It has a white wire so it's switched but not fused. The other wire is white/black because it gets grounded by the points. 
 

So even without a model specific wiring diagram, the primary colors give a lot of information. 
 

By the late 1970's, the cars started getting more complicated and a lot more colors and tracers came along. 

Carl Heideman said:

Keith Tanner said:

Aren't most Lucas-based wiring diagrams fairly standardized in terms of things like wire colours? 

Yes. Lucas does this really well despite all the jokes. Here are the main codes:

• Black - ground -
• Brown - always on, unfused +
• Purple - always on, fused +
• White - switched, unfused +
• Green - switched, fused +
• Red - parking lights +
• Blue - headlights + 

These assume negative ground. For positive ground (usually pre 1967) the colors are the same but polarity is opposite. 
 

After the main colors, Lucas then uses tracers. Blue with red is low beam headlights, blue with white is high beams. Another example is horns, which are usually two-wire with a switched ground. The + side of the horn is purple (always on, fused). The - side is purple with black where the black represents a switch that grounds the circuit. 
 

I can go on but it's probably time for someone to chime in with a Prince of Darkness joke. 

That is all awesome information to know, actually, so I'll spare the jab about how Lucas only sucked because they couldn't figure out how to make electrics leak oil.

Humans are pattern seeking creatures, we file that information more better than rote learning.  If you know the patterns then you can make a reasonable assumption about function.

So, have it all wired up per diagrams. And it works! But it doesn't. 

Fuel gauge inoperable, tach inoperable. I did put the resistance loop on the tach (there was no metal on it, just nylon) and tried shorting the sending unit wiring with no change on the fuel gauge. 

It seems that 67 midget coule be positive or negative ground, amd it will apparently run either way according to the internet. 

Is there any way to tell which way it should be? I got the car disassembled,  with no knowledge of how it was when last running. 

I have my bugeye negative ground, unlikely your issue, biggest difference is polarity of the generator and changing that is pretty easy. Moss has a video somewhere. I'll see if I can find it tomorrow. 

My fuel gauge isnt working either, there are different senders and gauges for different years and some are incompatible. I need to chase it to ground on mine. 

Want me to check how my tach is wired tomorrow? I have a later electric tach in mine and it's working fine.

My tach is labeled positive earth on the front, but im unaware if anything is changed inside. The fuel gauge never wiggles no matter what I do, pegged on full.

How do i check charging? Just the same way I would an alternator American car?

I switched my Rover to negative earth, it was ridiculously easy. IIRC you switch the cables on the battery and then spark the generator. And attach a label :

I don't think it affected the gauges at all, but the truck doesn't have a tach. 

Some help. Didn't get garage time today, I'll try tomorrow.

One more

If the fuel gauge pins full when it gets power make sure the lead to the sender is not grounded accidentally. If you disconnect the sender wire at the gauge and it still goes full the gauge has been murdered. The fuel senders often sieze mechanically, but are easily repaired. Also double check the tank ground, some cars never had a separate wire, and loose their tank ground when they loose their hard metal fuel pipe from the tank (!)  The bi-metal voltage stabilizer on the back of one (tach?) instrument is also a failure place, and the repro parts are iffy, I am 1 for 2 so far for good ones.