MGTC wiring loom

Discussion of TABC-related matters
Post Reply
User avatar
jddevel
Posts: 537
Joined: Wed Jun 20, 2018 11:48 pm
Location: cornwall uk

MGTC wiring loom

Post by jddevel » Tue Feb 22, 2022 6:45 am

I`ve a potential problem with my Octagon supplied MGTC wiring loom from I believe Autosparks who quote on their web page that "they do not supply fitting instructions as they are like for like replicas". That is not helpful when they for example include a green/brown wire which actually should be a brown and green wire-well if my analysis of what I`ve got is correct. However I am unable to establish the need for the two blue wires which disappear into the main loom but seem to terminate nowhere on the looms` tails but have continuity between the ends. Surely they can`t be the link between the horn push and dipper switch which logically would have been included in the dash loom. The dash loom incidentally I`ve given up on and fabricated my own due to a mix of colours and cables which logically should be there but are missing. Any help or suggestions please. Incidentally Auto sparks were no help at all without me being able to provide the "bag label part number" which has long since been disposed of. Certainly wouldn`t recommend or use them again.

User avatar
Franz Tenbrock
Posts: 543
Joined: Wed Jul 11, 2018 9:39 am
Location: Waltrop Germany

Re: MGTC wiring loom

Post by Franz Tenbrock » Tue Feb 22, 2022 1:46 pm

Hi
that s the reason i make my own loom

here colored picture, i think you have it

where did the blue wires end, is it possible that it is the connection horn dip ?

you have read the burned TD last week in mgexp
that is the reason i always switch the power with relays
and i don t use the ampmeter behind the dash

is it possible to feel where the blue wires where in the loom

in germay i have to have hazzard light and direction lights, so there are a lot of wires behind the dash original not there
i use proficad to make a colored wiring diagram, with this program it is easy to make two colors in one wire

good luck with your wiring, is it for the red TA ?
Attachments
tc.JPG
Best Regards
Franz

3D Print: CJR3 case for Lucas340, individual Titan-X spark plug holder, resin printed octagon hazzard light switch and some more,

User avatar
Ray White
Posts: 586
Joined: Fri Feb 09, 2018 2:22 pm

Re: MGTC wiring loom

Post by Ray White » Wed Feb 23, 2022 1:03 am

I was also bemused by that blue wire. I don't think it is connected to anything. I think it is just a single wire for the horn push to dip switch...and yes...I think it should have been included in the dash loom. :bow:

User avatar
SteveW
Posts: 315
Joined: Sun Aug 23, 2015 8:25 am
Location: Nottingham, UK

Re: MGTC wiring loom

Post by SteveW » Wed Feb 23, 2022 1:14 am

By process of elimination I concluded that the blue wire runs from the Ignition to the Horn/Dip switch. Not sure why it is routed through the main loom, rather than being part of the dash loom, but it is.

In the words of Sherlock Holmes "when you have eliminated the impossible, whatever remains, however improbable, must be the truth"

User avatar
jddevel
Posts: 537
Joined: Wed Jun 20, 2018 11:48 pm
Location: cornwall uk

Re: MGTC wiring loom

Post by jddevel » Wed Feb 23, 2022 1:17 am

Hi Franz, Both cables are in the group that end at the dash. There is no indication where the the two blue wires end other than they are either one cable or joined somewhere in the cloth covered loom. But for what purpose? There are cables for the headlights (bu/w) and dip (bu/r) so their is no apparent reason for them. Indicator cables are in place BUT perhaps you are correct and in some way they are for a hazard switch which would be helpful. I will have to check with the flasher cables which are gr/w and gr/r and r. According to any diagrams I have available the only blue wire runs from the ignition switch to the horn/ dip switch. It is for a `48 TC.

User avatar
jddevel
Posts: 537
Joined: Wed Jun 20, 2018 11:48 pm
Location: cornwall uk

Re: MGTC wiring loom

Post by jddevel » Thu Feb 24, 2022 12:17 am

Phew!! Not just me then. If it is Ign to horn switches and along with the other discrepancies makes me wonder if its all sound. If it wasn`t 80% installed I`d send it all back.

User avatar
Ray White
Posts: 586
Joined: Fri Feb 09, 2018 2:22 pm

Re: MGTC wiring loom

Post by Ray White » Thu Feb 24, 2022 12:47 am

jddevel wrote:
Thu Feb 24, 2022 12:17 am
Phew!! Not just me then. If it is Ign to horn switches and along with the other discrepancies makes me wonder if its all sound. If it wasn`t 80% installed I`d send it all back.
Don't be surprised if there is hardly enough wire to reach the dash AND have enough space to connect it all up. I have followed the example of others and bought extra wires to make a 'mini' loom with a multiplug.

This should make fitting and removal of the dashboard easier.

User avatar
timandgerda
Posts: 125
Joined: Thu Oct 22, 2015 12:50 pm
Location: Derbyshire/UK

Re: MGTC wiring loom

Post by timandgerda » Fri Feb 25, 2022 10:22 am

Hi Ray - have you got any details of the plug(s) you used for the main loom to dash connection? I am planning on going the same route when work stops getting in the way!

User avatar
Ray White
Posts: 586
Joined: Fri Feb 09, 2018 2:22 pm

Re: MGTC wiring loom

Post by Ray White » Fri Feb 25, 2022 11:54 am

timandgerda wrote:
Fri Feb 25, 2022 10:22 am
Hi Ray - have you got any details of the plug(s) you used for the main loom to dash connection? I am planning on going the same route when work stops getting in the way!
I have not done anything quite like this before so I am still learning from my mistakes. I chose a 15 way connector thinking it would be big enough but I ended up having to buy another, smaller one to cope with extra wires (flashing indicators, etc). I bought mine through eBay.

https://www.ebay.co.uk/itm/142033050277 ... 1135702666

Image

Don't forget to allow for the cost of all the wires you will need! They are sold in minimum lengths of 1 metre so you will probably waste half of it!

User avatar
Duncan M
Posts: 799
Joined: Fri Oct 10, 2014 9:08 pm
Location: Northern California

Re: MGTC wiring loom

Post by Duncan M » Sat Feb 26, 2022 10:47 am

I would never buy a commercially available wiring harness for a TC, because they are ALL trash. All the wires that have a grub screw or bullet connector were originally pre-tinned copper strand wire. The trash might have pretty insulation and convincing cloth wrap, but what is the point when the wire inside is all wrong for a car with grub screws and bullet connectors? Far better quality soldered connections are much easier done with pre-tinned wire. Grub screw connections are simple with pre-tinned wire. Many brands of higher quality pre-tinned wire out there. Often called boat wire.
14_AWG_Wire__93928.1535659141.jpg

User avatar
Ray White
Posts: 586
Joined: Fri Feb 09, 2018 2:22 pm

Re: MGTC wiring loom

Post by Ray White » Sun Feb 27, 2022 12:27 pm

I don't have an issue with tinning my own wires. What I do find frustrating however is that the braided (cloth) covering frays so easily. I find I spend as much time sealing the material as I do tinning the wires!

The cloth covering is also difficult (impossible) to keep clean.

Having said that, I am persevering with the Braided cables as they look more in keeping with the car despite being three times the price!

I must be a bit loopy. :wtf:

User avatar
Franz Tenbrock
Posts: 543
Joined: Wed Jul 11, 2018 9:39 am
Location: Waltrop Germany

Re: MGTC wiring loom

Post by Franz Tenbrock » Sun Feb 27, 2022 1:00 pm

i have made 2 homemade looms in the last 2 years
the first one I made with flry wires and cloth tape
but it was difficult to wind it
the second one was my masterpiece
there I used cloth wrapped wires from Autospark
put them in a tube slit lengthwise and then wrapped them around
this was much easier and went much faster and also looked much better
the cables stay so clean
the bullets I soldered which was easy and then sealed the ends of the cable with about 3 mm wide heat shrink tubing
went pretty fast and all cables are exactly as long as they need to be
for the rear I have inserted an additional power cable
then i can maybe install a wlan camera in the back
i would always make my own loom never buy one
Best Regards
Franz

3D Print: CJR3 case for Lucas340, individual Titan-X spark plug holder, resin printed octagon hazzard light switch and some more,

User avatar
Duncan M
Posts: 799
Joined: Fri Oct 10, 2014 9:08 pm
Location: Northern California

Re: MGTC wiring loom

Post by Duncan M » Sun Feb 27, 2022 4:54 pm

Franz-
Of course I used the original TC armour, and appropriate cloth covering where it comes out of the headlights. Cloth tape essential. I also used "asphalt coated cloth wire loom" in several places. It comes in all sorts of different diameters. I was able to re-use all the original chassis wire clips etc. when the new wires were inside the asphalt conduit! Flexible and waterproof.
I found it on ebay for reasonable price from this place: https://tonsperformance.com/products/as ... 4185512001

Post Reply