Bodywork, Paint, Interior, Trim, & Wiring

discussions about bodywork, paint, interiors, trim, audio, electrical components, wiring, etc.

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Richl705
Richard Lilly
Fairfax, Virginia
(38 posts)

Registered:
12/03/2007 10:48PM

Main British Car:
1958 MGA Buick 215 V8

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MGA Electrical Circuits
Posted by: Richl705
Date: July 30, 2008 10:28PM

I am looking at requirements for a wiring harness for my 1958 MGA 215 project. The universal harnesses available from Summit or Jegs are considerably cheaper than the one on Moss Motors. But the universal harnesses are sold based on circuits required. I can guess on a number of required circuits but does anyone know how many circuits there are on an MGA (with a Buick 215)? Thanks


Moderator
Curtis Jacobson
Portland Oregon
(4414 posts)

Registered:
10/12/2007 02:16AM

Main British Car:
71 MGBGT, Buick 215

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Re: MGA Electrical Circuits
Posted by: Moderator
Date: July 30, 2008 10:56PM

I think the original MGA came with about two fuses (not more than four)... but that certainly wasn't enough to be "safe". There are countless places in an MGA wiring system where a "dead short" would produce melted wire insulation instead of a blown fuse (and a full-fledged fire could subsequently result.)

If you're rewiring the car from one end to the other, I'd recommend that you plan on having about ten fuses.

Have you read this article? Dan Masters' tech session at the British V8 2007 Meet

Notice that Dan provided a chart... listing eight fuse positions and correlating them to the circuits they protect. That's a good starting point. In addition to these, personally, I would add either two or four fuses for the headlamp circuits. Frankly, this is a topic where well-informed and conscientious people won't necessarily see eye-to-eye. I wrote an article once explaining my opinion on the topic: [www.britishv8.org]

Here's some excellent late-breaking news!
You may have read in the last edition of British V8 that Advance Auto-Wire is no longer in business... but Steve Carrick has purchased the company's assets and will be continuing its operations. I think there's some backlog of customers that he needs to work through... but the Advance Auto-Wire product is second-to-none in quality, and I completely trust Steve to keep that up! Use the "personal message" system on this board to contact Steve - his UserID is "Barney".


V6 Midget
Bill Young
Kansas City, MO
(1337 posts)

Registered:
10/23/2007 09:23AM

Main British Car:
'73 MG Midget V6 , '59 MGA I6 2.8 GM, 4.0 Jeep

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Re: MGA Electrical Circuits
Posted by: V6 Midget
Date: July 31, 2008 10:17AM

Richard, if you are at least familiar with auto wiring then I'd say go for the stock harness and modify it as necessary for the 215. Unless you plan on running electron fuel injection then the engine hookups will be basically the same. You'll have to modify for an alternator, but that information is available for anyone converting a stock MGA or MGB to an alternator anyway. Check Barney Gaylord's site for information on the conversion. [search.freefind.com]
Adding a second or larger fuse block isn't hard to do for protection of additional circuits and relays.
The advantage of using the stock harness is that you'll have all the correct contacts for the lamps etc. Check e-bay as there are some harness that sell there at quite a bit less than the Moss or VB price, that's what I'm using on my project.
Not to knock the Advance Autowire system though. It's a great setup and is designed for the LBC of any sort, but if you keep the stock MGA turn signal box etc, the Advance harness will be a pain to hook up with that.
That makes three of us working on MGAs now, looking forward to seeing your progress.


rficalora
Rob Ficalora
Willis, TX
(2646 posts)

Registered:
10/24/2007 02:46PM

Main British Car:
'76 MGB w/CB front, Sebring rear, early metal dash Ford 302

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Re: MGA Electrical Circuits
Posted by: rficalora
Date: July 31, 2008 10:51AM

I've been considering the same & would love input on:

a) where would you add extra circuits (e.g., Curtis' recommendation for headlight fuses). Others I can think of if you're "updating" w/more modern features would be the ones below... what else should someone getting ready to rewire their car consider?
i) Electirc radiator fan
ii) A/C
iii) Power Windows
iv) Power Locks
v) door poppers (if you're shaving handles)
vi) stereo (if you're putting a higher powered one in)
vii) power antenna (if you plan for one)
ix) alarm system
x) ECU (if fuel injected -- now or potentially later)

b) where would you add relays? Certainly the ones below, where else?
i) Electric radiator fan
ii) A/C
iii) headlights


danmas
Dan Masters
Alcoa, Tennessee
(575 posts)

Registered:
10/28/2007 12:11AM

Main British Car:
1974 MGBGT Ford 302

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Re: MGA Electrical Circuits
Posted by: danmas
Date: July 31, 2008 12:01PM

V6 Midget Wrote:
-------------------------------------------------------
> ...but if you keep the stock MGA turn
> signal box etc, the Advance harness will be a
> pain to hook up with that.

Actually, the AAW kit for the MGA is easily hooked up to the turn signal box, and we provide the instructions for doing so in our manual for that car, and the kit includes all the wire needed for it. Our circuit retains the dual brake/TS function as the original.

I'm one of those who disagree with Curtis on headlight fusing. If you are going to use fuses, you MUST, in my opinion, use four, one for each filiment on each side. What ever you do, do not use just one, or just two.


V6 Midget
Bill Young
Kansas City, MO
(1337 posts)

Registered:
10/23/2007 09:23AM

Main British Car:
'73 MG Midget V6 , '59 MGA I6 2.8 GM, 4.0 Jeep

authors avatar
Re: MGA Electrical Circuits
Posted by: V6 Midget
Date: July 31, 2008 12:20PM

Dan, thanks for the clarification on the MGA system. I should have checked a little closer to see that you had a kit designed especially for the MGA with its quirks. Richard, in that case go with the Advance kit.


Richl705
Richard Lilly
Fairfax, Virginia
(38 posts)

Registered:
12/03/2007 10:48PM

Main British Car:
1958 MGA Buick 215 V8

authors avatar
Re: MGA Electrical Circuits
Posted by: Richl705
Date: July 31, 2008 06:36PM

Thanks to all for the info. I sent a note to Barney. Curtis, I had read that article and boy is that a scary bundle of wires! I like the idea of 4 fuses for the headlamps. I have also seen some nice work in the photo gallery for hiding all that wiring. Richard



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