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MG MGA - British Engineering or Insanity

Before I begin, this is not meant to insult the british members but some of the things on our MGA's are insane.
I am trying to connect the brown/blue wires that connect to the ignition switch. Both wires are # 10 (I think)and they must connect to the same terminal.
Well for the life of me ....how do you fit these two wires into a slot meant for one wire. It like trying to fit 10lbs of dirt into a 2lb bag.

Several of the engine bulkhead connections have the same problem. Yet at the same time some of the wires have terminal connectors factory installed. Insane.

Thank Gord
Gordon Harrison

Gord,
Out local premier LBC restorer advises soldering a single Lucas bullet connector onto a short heavy gauge wire from the switch and then using a two to one female bullet connector to join up the other leads. Don't forget to use dilectric grease.
BOL,
Doug
D Sjostrom

Perfect,makes alot of sense.I was so frustrated last night I guess I couldn't think straight.
But in all truth I think part of the love/hatred relationship with our MGA'S has to do with some of the "crazy" ways they were put togeather.

EX: Fitting the two finishings screws,on top of the frt bumper (that hold the ends to the main section)once the bumpers are on the car.Try to get the lock washer and the nut up behind the bumpers. EEEEHHHH.
Might have been easy to do when the bumper was fully assemled (when the car was new).
Gordon Harrison

That's interesting. My now retired Lucas ignition switch, that I have no reason to assume is other than original, has spade terminals!

Is this another example of varied original supplier equipment?
Steve Gyles

Mine WHICH IS ORIGIONAL has two small screw terminals inset into the base of the switch.This is what is causing the problem as the two wires will not fit into the small slot where I tighten the screw.

As a matter of fact,I dont recall a single spade or terminal connector on my dash electricals other than,and get this the ground connections.And all of my dash pieces are origional.
Gordon Harrison

I believe you find the same arrangement on the light switch--a brass screw tightens down onto each wire, pinching it in place. That is, untill the screw loosens and your headlights flicker when you go over bumps.
That's not reinforce the criticism, but to point out a potential hazard.
John V.
John Vallely

Doug's solution sounds smart to me, and who knows, may have been an OE method given the conditions.

John's warning about loose screw connections is warranted as I still have a couple small scars on my leg from a night of copiloting in a rally in a friend's MGA when his main wire fell out its underdash terminal, hit the dash brace, and in a shower of sparks (which burned through my jeans) we rolled over to the side of the road, dead in the water until he put the wire back with flashlight and screwdriver. More excitement than I would care to repeat.
Bob Muenchausen

There were no spade terminals on an A at all (originally). everything was with screw terminals, and used thread of 2BA. Some of the holes where wires have to go are ridiculously small for the quantity and gauge of the wires involved. I tend to solder and heatshrink seal the joints before the switch, and have a single wire go into the switch terminal. Heatshrink is much more robust and secure than insulation or wiring tape.
dominic clancy

Yes, looks like another item that was replaced on my car during its first 26 years of life in California. The defunct Lucas switch is old and decrepid and was in the car when it went to a barn for a 22 year sleep in 1974.

Apparently the S45 switch should have the month and year of manufacture on the black bakerlite.

Current reproduction Lucas S45 switches have spade terminals. I can vouch for that with my new one obtained last year.

Steve
Steve Gyles

I can't add up. I should have said the car's first 16 years of life in California, not 26.

Steve
Steve Gyles

When I spoke to James at Bob West's this morning he said that the manufacture date was either on the bakerlite or the casting. Just had a look at my switch with its spade terminals. The number on the casting is 31899B0772. This would appear to suggest that it was B (Batch) 07 (July) 72 (1972).

Going back to the opener on this thread, would this perhaps suggest not insanity but rather development? In those days it was common practice for MG to use existing BMC/supplier parts wherever possible to keep the costs down. It is therefore unlikely that this switch was developed for the MGA. More likely it came from another less sophisticated period BMC car and was 'made' to fit. In the course of time its shortcomings would have been identified, just as Gordon has outlined in his post, leading to the development by the supplier of a more suitable item. I believe that spade terminals were used very frequently in the MGB.

Steve
Steve Gyles

Steve,
I agree with your response and see the possibility of old parts being re-developed and improved. My use of the word "Insanity" comes from a night of frustration lying on my back underneath the dashboard. No personal insults intended.
A good example of improvements in the MG was the introduction of a fuse panel with more than two fuses. At present I am installing fused links in most hot wire situations. This all comes about from having nearly burnt my car up when the red light switch wire "shorted" and burnt the whole harness ...dash to the front of the car.

Dominic....Are there no round metal connectors on your black ground wire in the dash wiring harness? All of my grounds are equipped with these connectors.

Doug ,I made the connection ,as per your suggestion and Voila ...perfection. So simple I did not see it.

One final question.The brown/blue wire running from the ignition switch to the headlight switch creates a situation where the headlight switch is always "hot". Would it not be more acceptable to connect the brown/blue wire FROM THE LIGHT SWITCH to the IGNITION CONNECTION having the two white wires.Then (using my terrible electrical knowledge) that would make the light switch "hot" only when the key was turned. Gordon
Gordon Harrison

Hi, Gordon - re: your last question, no switching contact is perfect - they all have some built-in resistance. Therefore, all switches (including relay contacts) have two important specifications regarding the current they can handle in both "switching" and "hold" conditions. A higher current creates more heat at the contact point, and the switch can fail if the rating is exceeded for too long of a time.

I'm reasonably certain this is why the lighting circuits are not routed through the ignition switch, but there may also be an underlying safety issue where one would not expect the lights to go off if the ignition switch is rotated.

However, if you use relays to power your headlights, I see no reason you could not use the ignition to power the relays, since they would add only a small additional load on the ignition switch. I once had my halogen driving lights wired through the headlight's hi-beam, so that when I dipped the bright headlights the driving lights went out as well. Worked great, and was a large surprise to those impolite people who refused to dim their lights until I "reminded" them.

Best of luck - - Alec
Alec Darnall

The idea is from Steve Mackay, a well respected restorer outside of Boston.

http://www.mackaysgarage.com/
D Sjostrom

Gentlemen - The comments on this thread reminds me of a card I once found in the packaging of a new piece of electronics equipment we were installing on a Naval ship years ago. the card said "Your critism of this product reveals an unsound technical background". British engineering or insanity - I would have to respond with, neither, just the state of the art at the time the vehicle was being manufactured, thankgoodness we have progressed in the intervening years. I found the same problem with the wiring of our TD and believe it or not, I was able to get all of the wires under the grub screw stripping each wire a bit long, each wire down with a screw slightly smaller than the grub screw, then screwing the grub screw down to completely seat the wire. I then removed the grub screw and repeated the process with the other screw. This was a long and tedious process and one that I'm not sure I would repeat if I had to do it over again. The suggestions of splicing the two wires to a single one to place under the grub screw makes a lot of sense.

As for 10 pounds of sand (we always refered to a different product) in a two pound bag, you haven't lived until you have worked on a submarine. We didn't stop at ten pounds, if we couldn't make twenty pounds fit in, we usually wound up working overtime until we found a way. Cheers - Dave
David DuBois

This thread was discussed between 22/06/2006 and 24/06/2006

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