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MG TD TF 1500 - Replacing Harness

Just curious if anyone has replaced the TD wiring harness "in situ," (while the car was fully assmebled)? Seems like a "doable" task, but I'm sure there are problem areas.

Just last night I was replacing my ignition/lighting switch and it was more hassle than I anticipated (replacing the clip). Of course I chose not to disconnect the choke and starter cables, but I can't say for sure that was what was holding the facia nearly vertical away from the inner board. I undid the speedo and tach cables as well as the oil line for the gauge. In any case, it's in.

So, as none of my wires still are coded (all faded out), the outer braids are somewhat brittle, a new harness would be great. However, I do not want to wait the years it will be before I disassemble the car for restoration, as in my view it's a long way from needing that. Any input and experiences appreciated.

Larry
L Karpman

Believe the center gauge panel was installed after the dash, alhtough I have done a few things underneath and found it a pain, perhaps undoing the center panel and leaning it forward might be easier?
gblawson - TD#27667

Thanks Gordon. I'm done with the panel for now. Didn't mean to mislead by describing my situation last night.

I'm speaking about replacing the "entire" wiring harness for the whole car, without the car being disassembled.
L Karpman

Yes, I understood... would be easier to do it with the panel pulled out then laying on your back under the dash...!
gblawson - TD#27667

So, there are no issues with running the harness to the front and rear lighting, etc. with the car totally assembled? No other isues except the dah wiring?
L Karpman

Your question about the harness color coding. I had purchased my TD harness from Moss. The harness was color coded s in the TD/TF workshop manual.
A Thienes

You might find this site interesting... all British wiring follows a colour coding...

http://homepages.tesco.net/~JEC.WNO/Workshop/circuitColours.html
gblawson - TD#27667

Thanks Gordon. Fortunately with 20 years of Jaguar ownership I have traced many a wire on a British car :-) I had never seen this site before though. Invaluable good stuff!

My "main" question about the harness though is any difficulties in "stringing" the harness throughout the car, while the car is fully assembled. As I said in my original post, it "looks" straightforward, but I wanted to know if anyone had first hand experience doing it with the car assembled.

Thanks again.

Larry
L Karpman

I think if you start at the firewall and feed the interior stuff through the hole(s), getting the rest around the car is pretty straight forward...I know i have traced most along the frame and back to the various clusters of connectors.
gblawson - TD#27667

Hi Larry,

As Gordon says it is pretty straight forward. I replaced mine a couple of years ago with virtually no problems. As I recall the only place that required a little time was where the harness runs to the rear, between the pedal box and the frame. Years off accumulated crud was the primary culprit there. Tim, 53 TD
Tim Mayor

I'm pretty lucky there. The frame has virtually no "protective" crud :-)

Larry
L Karpman

I find that the easiest way for me to replace wiring in situ is tp remove steering wheel and the glove box. Then undo all the screws holding the dash panel in place. Wrap the steering column so as to not damage the instrument panel . Lay it down and go on with the wiring. All the rest is easy as you follow the original paths. be certain that you have the needed clips that go along the frame twoards the rear.Also the rubber grommets. The color (colour) codes are easy to follow.
Sandy
Sandy Sanders

Thought I would take a moment to ask a harness question unrelated to the origional post. I thought I read something in an earlier post about the harness being in seperate parts. I don't know how else to write it. If I order a harness from Moss or another supplier, is everything I need to wire the entire car there including the dash.

Texas Rob
Rob Welborne

Sandy: To me the dash would be the easiest part once it's laid over. I was concerned about hidden problem areas. As best I can tell, the wiring going forward to the front lighting is not a major deal. However, as I have not had my car up on a lift, and only been under certain portions on my back, I was not sure if I could access the area on the frame that the wiring is strung to the rear lighting, etc. back there. You have answered that question.
L Karpman

Rob:

As I recall when I ordered my harness from Moss it came in two pieces. They connect with the plug-in connectors so it's relatively straight-forward. The Moss kit did not include the sub-panel wiring nor was there sub-wiring for the (TF) wiper motor. The harness does bring power to the two areas but I had to then fabricate the sub-wiring harnesses. They are easy to do...just sketch yourself a diagram from the old wiring on the panel. I believe in some earlier threads there is at least one other supplier (can't recall who it was) that also provides a harness and does include the sub-panel harness. The main harness also provides a wire connector slot to power additional fog/driving lights.

Cheers,

Jim
Jim Rice

Try Rhode Island Wiring Service, http://www.riwire.com. Top notch quality.
Yes, Larry, the entire wiring harness(es) can be installed "in situ". Releasing the instrument panel makes life much easier.
Bud Krueger

They put my late TD complete wiring system at $835.00?
Moss does have the set (probably less the battery/starter/strap items) for $363.00
gblawson - TD#27667

Here is another 'tech' link regarding wiring on pre '50 (?) British wiring with a number of suppliers of the proper colour coded wire at the bottom of the page...

http://www.team.net/sol/tech/LucasColours.html
gblawson - TD#27667

one thing to remember, the harness goes ABOVE the roll frame. I forgot this 30 yrs ago and when I tried to to remove the tub from the chassis 5 yrs ago I nearly ripped the instrument panel apart. I now routinely photograph everything!
RAY LEE

There are three parts to the complete wiring harness for the TD: the front, the rear and the under dash. I bought mine from Auto Sparks in the UK. To order, you need to specify the following options: LHD or RHD, turn signals or not, hand or foot operated dip switch and main beam warning light or not. Also you will need to order one extra flying lead, the wire from the coil to the distributor, white with black streamer. The fog lamp wire comes as standard. I had no problems replacing the complete wiring with the car assembled.
John Scragg

Thanks John, I have emailed Auto Sparks for a quote. Would I be wrong/correct if I started at the dash wiring, then pulled through the firewall to the lower left side of the engine bay where it brances to the left front lights, the right front lights, wired them, and then took the remainder along the frame to the rear? I know that's a basic description, but seems a possible method.

Larry
L Karpman

Larry... are you doing all this to the beautiful 'red' TD in the photograph?
gblawson - TD#27667

Thanks for the compliment Gordon. Yes, the TD needs some TLC in some areas, and the tattered and dried wiring is one of those. I have spent the last month or so mainly on small electrical, gauge, and chrome bits issues. The wiring though will continue to become a greater issue. I will say that although the outer wire coverings are somewhat dried out and lost all of their color coding, the actual inner wire coating and wires themselves are in decent shape. That said, not having the color coding makes things much more difficult. At some point I will need to do the wiring, so I thought I'd get the info now.
L Karpman

Larry,

Yes, that sounds fine. You should not have any problems doing the rewiring. One thing I did which turned out to be a big time saver, was to leave a few inches of old wire on each component and if the original colour is not
visible, add a label marked with the required colour, that way all you need to do is connect the new colour coded wire to the equivalent label.

John
John Scragg

$835.00 is a huge difference from $363.00. Is it worth the extra money you paid?

Texas Rob
Rob Welborne

I would also suggest laying the new harness out on the floor and determining where all of the ends go before installing it. I went a step further and tagged each wire as to where it hooked up after having confirmed each wire with a multimeter. Cheers - Dave
David DuBois

Jim,

I am still new at this so please forgive my ignorance about all the MG lingo. When you say sub-panel do you mean all the wires behind the center of the dash? Mine has been half apart for 25 years so there is no copying what I already have. I assumed that when you bought a harness every wire was there for every light, switch, and gauge.
Rob Welborne

Rob:

Yes...that's what I was referring to. The harness from Moss stops short of providing instrument light wires. There are only a few so fabricating that "sub-harness" is not difficult.


Cheers,

Jim
Jim Rice

Not too bad to replace the harness with the car whole. You can get the insturment sub-harness from Abingdon spares, comes with a nice diagram. George
George Butz

I replaced the harness in my sister's TD about 20 years ago with the car whole. Not a hard job. The worst part was the laying on the back under the dash and the hot solder dripping on the forearm. Ouch.
Carl Floyd

Larry,

I'll be installing my harness after my tub is in place. I will wire up my instrument panel and fascia before I screw it into place and then install my steering wheel and column. I would be tempted to remove those items if I were doing the job in place. There is a lot of good adivice about testing the harness, including using a low current battery charger before you actually hook it up to the car's battery.

I just recieved my harness from British Wiring, www. britishwiring.com out of Olympia Fields, Illinois. The harness looks super. I had them build me a harness for the five post regulator, no turn signal and dash dip switch in braided material. To this I added the provisions for the eight way turn signal flasher with an extra long wire for the indicator lamp. I plan to place a buzzer instead of a lamp. I also ordered a dash sub harness, an engine to ground cable, a master switch to solenoid braid, a battery to ground ground cable, a battery to solenoid braid, a bunch of single snap connectors and a wiper motor lead. My only disapointment is the wiper motor lead, it is purple and black braid, rather than gray. I may use it.

Total cost including shipping, under $500. The modifications I ordered took and extra four weeks.

warmly,
dave
Dave Braun

I got a quote from Auto Sparks in the UK. Every harness, sub harness, engine bay wires, etc. for a '53 TD with foot dipper and turn signals was about $430 under current exchange rate, but that includes nearly $100 to post to the US. Not bad, but I'm really not willing to pay that kind of shipping cost unless I need to.

I'm about 6 month out on doing the harness I believe, so all of the info here has been most helpful. Thanks guys.
L Karpman

Dave,

You said you ordered your harness without turn signals. Then you said you had it made with eight way turn signal flasher. I don't understand. Also, could you have ordered it with hazard flashers or does that sound dumb?

Rob
Rob Welborne

Larry -
What I did was to cut about 6" of each of the wires that connect to instruments on the dash board and install klampons (or spade connectors) to them.

Install the 6" pigtail to each of the instruments and put the dash in place. Then just plug the spades together from the main loom.

Should I have to remove the dash, it will make it alot easier, than wiring up to the posts upsidedown on my back.

I started trying to be really slick by buying a "molex" type connector from Radio Shack, but the differences in wire gage didn't allow me to use it. If I was more motivated, I could have found a multiple wire gage connector from digikey or mouser.


Blair
Blair Weiss

Rob,

The harness I ordered was correct for my car, as I needed a panel mounted dip switch. Then I had it modified as they built it with turnsignal provisions, including an extra long indicator lamp wire which I will wire to my buzzer.

All of their standard harnesses with turn signals had floor mounted dipswitch provisions.

I was also able to choose the side of the fire wall I was placing the eight post relay. I choose the interior side.

I hope that is more clear!

I didn't ask about warning flashers, as I didn't intend to add those.

warmly,
dave
Dave Braun

This thread was discussed between 30/09/2006 and 07/10/2006

MG TD TF 1500 index

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