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MG MGB Technical - Creating a 'brown' junction box for live feeds

Hi all

I have recently discovered that the thread on my starter solenoid was stripped, which was the cause of a misfire problem i had (thanks everyone who contributed there!). I probably did this when i fitted headlamp relays <emabarressed face> as the thread strip is just where the nut/washer sat once the two relay feeds were installed on the solenoid lug....

Anyway i managed to get a good connection at the solenoid again by removing some washers that were on the lug and moving the combined connectors down the lug towards the solenoid body. So far so good.

However, i am about to fit some new main beam lights, thinking that these will need a new relay feed (most likely taken from solenoid again) and that any more connectors at the solenoid will put me back in the stripped thread area.

So i was thinking of running one large take off from the solenoid to a box connector, where i could run as many seperate brown wire off to those *extra* circuits needed. These would save adding connectors to the solenoid and mean i could add more browns into the box connector if needed later. I suppose its like a big fuse box with one input and many outputs, but without the fuses. I would then adapt current relay feeds to connect into the junction and also fit new relays to this also.

Is this viable, sensible, waste of time??? Would i be better buying a new solenoid without a stripped thread?? Sooner or later i will get to too many connectors and have to revert to another trick.

I rather like the idea of running all browns for extra circuits from one point however. What would be the best hardware to use for the job - could an MGB fuse box be adapted so as to look authentic, maybe the kit car people have something like this..? Using multi-bullets seems a bit old-fashioned, but assume it can be done this way - although the wire gauge i have used fore relays etc is quite thick....

Anyone have any opinions of all this??

~PHIL
Phil

Phil. I would replace the solenoid. However, your idea of making a junction box for the brown wire circuits is very interesting and, in my opinion, an excellent idea. It would seem a very elegant idea. Paul Hunt may have some ideas on what best to use and how best to set the system up. You might go to his website and drop him an e-mail requesting he respond to this thread. You have a very excellent idea and I am also interested in what you will find. Les
Les Bengtson

Les

Thanks. It does seem amazingly simple, which usually means i have missed something! ;->

However whilst i agree changing the solenoid would probably be the most simple solution, at present, apart from one very tiny part of the solenoid lug thread being stripped the unit is fine and appears to work without problem. The misfire and rev counter wobble have all now been eradicated.

So as there is always something to spend money on with the car, i would prefer to leave it be for now. However if between us we cannot work out a junction box style solution and i need to wire my main beam lights to the solenoid, then i guess i will have to purchase a new solenoid.

Rgds ~PHIL
Phil

Hi Phil.

The standard fuse box really isn't super reliable at the best of times, plus the maximum continuous fuse current rating is (I think) 17A.

I suggest you take a trip to the breakers.. some modern cars have a separate fuse box for the brown feeds, with a single input connection and three outputs, each of the outputs having it's own fuse.
I seem to remember that some more recent Metro's have a useful one.

There are two common fuse types used, one being an oversize blade type, the other being simply a strip of metal with eyes at the end that are screwed to the terminal block.

Either type of fuse comes in a variety of ratings, grab a selection (including some spares for the toolbox) from the breakers while you are there.

You might also like to recover some brown wire, and maybe some of that slotted conduit to keep things tidy.

Don
Don

Phil, I made a terminal block for several common feed points for my car and it is easily done. You will have to decide on the exact configuration however. You will need some phenolic material. I cut a chunk from a 3/4" thick sheet I had picked up at a plastics supply house. Thinner will work but not as well. Locate your preferred attachment points. Since I no longer use the stock coil I used that location and drilled to match the existing nuts. Then for your main lug get a stainless steel carriage bolt a couple inches long in whatever size you prefer. Using a flat wood bit, counterbore the back to recess the carriage head far enough that it cannot contact metal, then drill through, insert the bolt, flat washer, lock washer, and nut, then add a second nut and you've got it. Trim the bolt to the preferred length if you like. A piece of brass sheet for a jumper will allow the addition of a second lug of smaller size done in the same way. It will not look original, but it will be highly functional, and if you are particular about your work it can look very good indeed.

Jim
Jim Blackwood

Phil,

Another option:

http://www.madelectrical.com/catalog/cn-1.shtml
Dan Masters

Phil - If you want to go all the way with tis mod, contact Dan Masters at DMPublications@aol.com and ask him to send his booklet on Custom Wiring Panel for MGB V8 Conversion. This is truly a work of art and would cure a lot of the wiring problems in the MGBs. Oops, never mind, I just looked up and find that Dan has written a post already, so you can reply to him right here. Cheers - Dave
David DuBois

Dave,

Since you've already mentioned it, I guess no one will get upset if I mention that I now have a few of these wiring panels assembled and ready for sale. If any one is interested, they can contact me offlist.

(thanks for the kind words)
Dan Masters

Ahhh, Great ideas chaps!!

I was thinking along the lines of Dan and Jim there, although i must admit i was thinking of a plug type system, with four seperate outputs, easily marked and one single input. Linked by strip metal between points i guess and maybe plastic covers seperating them. Mind you with the vibrations the little B's get, then its probably worth having them all bolt fastened rather than push fit..

Any more ideas, it would be great to make up a good archiveable post here. Otherwise thanks a lot for these gems!

~PHIL
Phil

Phil,

I have done a variation on what you are thinking of. A purple (ie always live fused) ring main. I don't like lots of brown (ie always live unfused) wires running about. Also my wire from the altenator to the starter has had to be changed in the past through getting too hot.

So I have installed an extra brown lead from the spare terminal on the altenator to the starter motor via a double fuse block. It loops in to both fuses. The fuse block is mounted next to the washer motor on the inner wing just below the top flange. The purple ring main follows an L shape route gong to the front corner and then across, under the slam panel to the other corner and back again. The various relays are hung off it along the way in places close to the item they are feeding. To minimise the number of solder joints I use the flag shaped female spades at each relay and cut off a short section of insulation to solder the joint as the wire passes through.

If I remember correctly, the ring has a 30amp fuse at each end. Each item fed from the ring is protected by its own lower amp fuse. This can be done quite neatly if you use relays that incorporate a fuse holder.

I designed this set up to supply an electric radiator fan, to improve the brightness from my head lamps, reduce the load at the light switch and to feed some extra lights.

David
David Witham

Oops! I forgot to mention - if any one would like a copy of the "how-to" instruction manual to build your own wiring panel, it can be downloaded from my website. Go to:
http://www.britishv8.org/techhome.htm and click on the electrical button. This is the same panel I sell, but there's no reason you couldn't build it for yourself. The manual contains complete plans, including a parts list, for the DYIer. The nice thing about building it yourself is that you can customize it to fit your needs.
Dan Masters

Take a good look at the older Saturns (94ish SC model) in a junk yard. You should find two fuse panels there. One is on the "hump" next to the passenger's feet. The other is under the hood on the driver's side. The one on the hump has relays as well. Infact, I like the location too. On my 79B, I may use one from a Saturn and place it on the inner hump of the B.
kids1

My other first love is boating. When yachties get together, they either talk about diesels or electricals. I would suggest to people buying electrical parts, wire lugs, connectors, terminals to check out chandleries (marine stores) or on line marine catalogs for the best quality in parts. Most marine electricals are designed to operate in moist salt air and therefore are made to endure it. If I were to rewire my B this is where I would go look to purchase my supplies. It will be more expensive but in the long run its worth it.

fwiw
CW
CW Strong

Kids1 wrote:

"Take a good look at the older Saturns (94ish SC model) in a junk yard. You should find two fuse panels there."

The only problem I have with using parts from another car is the problem of interfacing the wiring between them and your car. Usually, it involves a lot of splices. Nothing wrong with well done splices, but they are a bit messier than I like.

If you do get a panel from another car, try to get as much of the wiring as you can. The longer the leads are, the less need for splices. If you can get the leads long enough that you can make all your connections at a terminal, you're better off.

As a side note, EZ Wiring is having a sale on their wiring harnesses, only $165 right now. 18 fuses, 21 circuits, two flashers, and one relay. See: http://www.ezwiring.com/ This is basically the same harness as Painless Wiring sells.

Personaly, I like more relays than that, but you could always add them on.
Dan Masters

kids1,

I didn't mean to imply that getting wiring from another car isn't a good idea. If done right, it is an excellent choice.
Dan Masters

Many years ago, I ran a short positive battery cable from the starter to a 4-terminal block with 1/2" terminal screws. It allowed me to give/get jump starts without pulling the battery cover and hoping the cales would reach that far.

I still use it as a point for battery charger hookup and power to various tools (timing light, tach, etc).
Dan

This thread was discussed between 13/10/2003 and 14/10/2003

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