Coil Wires Configuration for my 79 B...

Yo Guys,

I will be re-installing a new coil soon for my 79 B -- as I have the new Pertronix Coil and Distributor add in unit. Prior to this, I had a 'points' set up. I have dual SU's - HS4's. I was NOT experiencing any issues with ignition problems. I am in the process of re-fitting everything back in the bay - as I removed everything to prep, mask, paint, now just hooking everything back together!

I need clarification on the [individual wires coming off of the harness] and clarification on the wire leads coming from the distributor to determine exactly where they are connected.

A: [The first image shows the COIL]: I realize red is positive, black is ground, though I need to ensure which wires attach to which posts, on the coil? I have designated with arrows, which post is positive & negative and the leads coming from the distributor [not shown]. The bottom two posts are the ones I am not quite sure of...see next image...on the wires coming off the harness...
_______________________________________________________________

B: [The second image showing the wires TO THE COIL coming off the harness]. I have numbers in yellow boxes, with arrows pointing to the wires.

# 1. White wires, green stripe (two wires going into one lead) and when I removed it from the original coil, I marked in bottom right of coil.

# 2. White wire, black stripe. I had this marked bottom left of coil.

# 3. This piece [metal part with connector on right side] was simply underneath the bolt that secured down the coil. What is that thing? The left side of that part did not, have a wire connected.

Also, I need to ensure I don't hook it up incorrectly! I've been diligently redoing my engine and bay -- and when it is complete, about 10 hours away, I will unveil the masterpiece to all! Thanks, Dan

Dan,

It's midnight here and I'm relying on memory so don't hook anything up until the following is verified.

I'll answer the second part first:

#1: the white/green wires (actually w/lg); one is attached to the starter solenoid and the other goes to a "ballast wire". This ballast wire then connects to a distributor resistor via a white wire which I believe is that metal thing in your picture. I can't tell if that wire is indeed white with no stripe. These w/lg wires should have been attached to the positive side of your coil.

#2: White/black wire (w/b); attaches from the negative side of your coil to your tach.

With the new Flamethrower coil, you should hook these wires back up to these terminals. As for the Pertronix, IIRC, the red is + and the black -. The Pertronix manual should tell you this as well. I can check my manual in the AM just to make sure. I can't imagine Pertronix would build a system that would go against the obvious but always good to double-check.

With the terminals you have on that coil (2 posts each), you've got enought to hook the wires up.

Have a look on page #25 of the Advance Autowiring website. This is where I found that ballast wire and distributor resistor. I have no experience with these so can't tell you if you need this hooked up or not.

read jeffs post below!

DO NOT use the ballast resistor with the Pertronix coil and ignition! You just bought a 3 Ohm internally ballasted coil, so use it with NO extra ballast.

I would eliminate the old pair of green/white wires and run a new wire from the green circuit at the fuse panel to the + terminal of the coil. Then hook up the Pertronix wires as described clearly in their wiring diagram. Its found in both the box you have, and on their website!

The only connection left will be the tachometer. Its the black/white wire that connects to the negative side of the coil, although the car will run without it. Every other connection is essential for the car to run properly!

Dan, I'm sure you already know this, but Jeff is THE expert. If you didn't buy your stuff from him, you own him a beer.

i wired around the ballasted wire by adding one directly from the ignition relay to the coil pos ,seems to work good , gives 12 V switched all the time to coil/

the item marked # 3 above is a left over from when the OE electronic ignition was installed, i removed it and threw it in my junk box. [the ballisted coil feed is a different wire,[w/lg] the resistor section of that wire is hidden in the loom on my 79] I think if you study the wiring diagrame and test w /multimeter i think you you will find the white is a 12 V switched by ignition which could serve to go to the coil pos. [ i fed a petronix with it once upon a time] However since i spread all the loom in the area i was dissatisfied with the circuitous routing of that white and the age /brittleness of the insulation, so i added the igniton relay to coil wire mentioned above.


item marked 2 is , i think the tach wire , goes neg on the coil

item marked 1 are the wires that energized the coil pos.
in original config. , in run setting the coil was energized by the ballested wire[ less than 12 V] , in start the coil was energized by a 12 V for boosted start situation .

better listen to Jeff, he is the man in the know, i am only a crudmegon contrarian , and have fried more than one petronix in my time.

i kept the w/lg's in the loom , it could be i will decide to return to a ballasted system some time, i have a bucket full of ballested coils i could choose from, from OE to Bosch Red, running an unballested Lucas Sport just now,
somewhere in the loom arm that goes from the big juction area towards the alternator there are some confusing wires in some short arms of loom ,the short arm had /has 3 as i recall that went to the OE electronic distributor, plus the 2 w/lg,, that went to coil ,ther tac w/b , in addition there is a big fat green [switched by ignition] that went to the induction heater, this one is another possible to feed 12V switched to the coil pos]

smart money would get a multimeter, a wiring diagrame for a 79 then spread that section of loom and identify each wire in that section of the loom as to original purpose , there will be some left overs with no where to go, ,

a misconnection to the coil/petronix will fry it in a new york second..

michael

Hi Guys, (especially Jeff)...my brother name as well! I will re-read the responses. I'm a complete laymen here with coils, connections, etc., so pardon my ignorance, it runs deep. I will not hastefully hook things up. I want to do the simplist, safest approach to hooking things back up.

I will not fry my system I announce! No! I will take my sweet time and make sure. I don't inherently understand or make sense of 'wiring diagrams?' I'm expert at fitness, but not electrics. I'm detailed yes, but electrics stump me. So -- I will slowly, (after the intimidation wears off) carefully move through the process. Any additional explanations would help.

Thanks, Dan

think of the wires as nerves..
......
on the petronix ignitor

http://www.pertronix.com/support/manuals/pdf/ignitor12vneg.pdf

quote
Connect the Ignitor black wire to the negative (-) side of the ignition coil.
Connect the Ignitor red wire to the positive (+) side of the ignition coil.
end quote

the pos side of the coil will get 2 wires , one will be the red from the petronix in the distribitor the other will be a 12 volt that switches on and off with the ignition switch


the neg side of the coil will get 2 wires , one the black wire from the petronix in the distributor , the other goes to the tachometer to make it work, .

.... the tach wire is the black and white one , i am sure if i say wrong some will correct me ,..

the petronix wires are well identified.

so all you need to do is identify a 12 volt that switches with the ignition switch ,

you can do this by wiring one in or by identifying an existing one , i think the white that goes to the item marked # 3 is a good candidate , but it needs verifying .

for sure the white/ light greens are not the ones , they are part of the ballested ignition system , so tape them up and mark them. [ballested ignition system [ coil positive]


multimeters are inexpensive and not so hard to use, get a multimeter [ 20$ ] a copy of the appropriate wiring diagram , a half case of beer ,

push the car out open the hood get the manual out, open a beer , wait , in a good neighbor hood your buds will be over pretty soon to score a beer,. and perhaps run those multimeter tests for you , i would do it but its a long way from dover to portland and remember , i have cooked two petronix already ..

and i am glad of it ..
michael
dover
tn

Yo Michael, Thanks for the encouragement. Nerves, good analogy. Based on what you said, concurs with the posts expert from what I gather, the [white wire with green stripes] is coorelated ONLY with the old ballasted system? hence their non-pertinence (unless I want to fry my system), yes? I do want to learn about how the heck these wires operate for future reference. First things first!

I've dug deep into the function via having to remove, replace many things in the engine bay, but electrics are an area that have a certain intimiation-factor to them that keeps me from diving as deep into them, as say - the carbs, which I can take off and replace with minimal issues. Thanks, Dan

correcto... the two white with light green stripes that are together are the ballasted system, one gives 12 Volts while cranking , the other gives @ 9 Volts ? in the run position...this ballested /non bvallested confused me a lot , so i undid the loom and traced wires , they are routed very oddly to me ,

so you will hook the petronix up to the coil ,,
black to neg
red to pos

hook the white with black stripe [tachometer] to the coil neg

then either wire in or identify a 12 volt switched wire,, .. like i said ,, i got a big can of fosters says that white that goes to the goofy left over resistor MARKED ITEM # 3
WILL FIT THE BILL .., take item # 3 off and chuck it in the junk box.. .. the testing verification would determine
first .. that wire is switched on and off by the ignition switch,
second , supplies 12 Volts while the ignition switch is in the "run" position, and in the start position.

i did not like the condition that white was in my loom so i wired a BIG FAT YELLOW wire straight from the ignition relay to the coil .
what will cook the petronix in an instant is if you feed 12 V to the coil neg while the petronix is hooked up , thats what i did , i decided that was too fragile to me , i have lots of senior moments ,, old timers disease they say it is..

m

http://www.advanceautowire.com/mgb.pdf

i was just looking at a shemat at above,, if you look at one be careful, lots things different the way they cam from the factory and the way we find them now..

fom factory there were two wb[ white black stripe] to coil one went to the tach , one to the dizzy . the item you have as # 3 had white w/ blue stripe [WU] that went to the dizzy , the dizzy also got another white. all these are fed by a white with brown stripe[wn] from fuze point 5 thats the second up, forward, that point is fed from the igiton relay c2 by a white w/ brown stripe , ..

so this white brown from fuze block 5 is fed from c2 of the ignition relay , thats the wire we want ,switched by the ignition switch .. it feeds the ballasted white w/ green strip , the white that goes to that resistor [ ident in the dia. as " distributor resistor' ] another white thta goes to the dizzy ...

ha haha .. i am right .. that white hooked up to item you have marked 3 , if it is still intact , will work , tale the dizzy resistor off and use that white ,, so say I ..
I figure i won that fosters in the ice box fair and square now..

Yo Michael! Yo...you are into Distributors...Dizzy, funny! You ought to write a rap about dizzy's in the B don't ya see, cause when they fire up they run like the wind, when they don't they blaze in a cloud of smoke covered haze!

...I think I partially understand what you said (not you, my ability to comprehend your words).

I haven't touched my distributor set up...yet. I just got the right securing bolt to hold the dizzy around its bracket, after I carefully painted the bracket a gloss black!

I will re-read your last post...I have a fitness client to coach in one minute!

Thanks, Coach Dan

you will know as much as i do if you study the diagram and read the manual .. probably more since i forget every think from one day to the next and have to learn it all over again,, since i learned it 50 times before i am a quick study ...heh..
look at the drawing linked above , for my 79 i look at late US Market MGB, its the next to the last one,

lots of stuff on that we/I do not have any more, of course the distributor/ignition shown is the OEM lucas electronic ..

i was not encouraged by the condition/length of the white wire that went to the distributor resistor , it was long and old and small, thats why i jump wired in a fat wire straight from post C2 of the ignition relay[ has a white with brown stripe on it ] , thats the one feeds the fuze Jeff recomends you take off from, its the second up with the green wires[ there is a green wire very likely available in there,, the one i speak of energizes the induction heater , which is very likely inoperative, that green is fuzed,switched from ignition and would work at coil positive , i was disinclined to use it since if the fuze blew i would be down on the side]

i undid the loom wrap took out some wires i did not like , led the wire from C2 down to the coil , wrapped the blue plastic back. shorter wire run with a little bigger wire should result in better power at the coil..


i must be telling you correctly since there have been no corrections,,

i an a true x-spurt .. you know what an X-spurt is do you not ,,
X = an unknown quanity
spurt i= a drip under pressure
thus an X-Spurt is an unknown drip under pressure..


hahahah


mrb
dover
tn