ballast resistor wiring

13051001.jpg


"Note when fitting: black/red wire to terminal 15 of ignition coil
green wire to terminal 15 of ignition lock"



http://www.e9-driven.com/Public/Library/BMW-E9-Manual/pages/en/12130510.html#refertoc
 
Ballast resistor

Earnest,

It doesn't matter which way; it's not directional. The resistor changes the voltage from 12 to less for the points.

One side will be the 12 volts, the other side goes to the + side of the coil.

If you're going to stay with the blue coil; just stick the 12v straight on the + side of the coil. The original back coil is better; the red coil is best.

I still say you're too advanced ( Popping and lean- throttle plates open no more than 1/2 turn) and the carbs aren't set up.( rich- float)
 
Here are some pics i took the other day when I put in a red coil.
 

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thanks all for your help, the owner of the Independent BMW shop(A++++ according to local BMWCCA chapter)where the engine was swapped out, will take the car down the street to National Carburetor whom is also a weber distributor and production carburetor rebuilder to have the jetting checked.
 
Coil

I replaced my black coil with a "blue" when I did the Pertronics, mainly because my coil was looking "rustic" I was under the belief that the blue was the way to go (memory from my Volvo days) Never heard of the "Red" Please explain if you can why the red is superior and what is the availability of this coil?
 
The original Black coil has no internal resistor, the replacement is the red coil which comes either red with silver label or silver with a red label. The blue has an internal resistor so if used disconnect the ballast resistor.
 
I believe the red is higher output than the black also but like Chris said it requires the ballast to be left in tact. Blue = no ballast.
 
Coil

Interesting...my car is a 1974 CS converted to 3.3 d-jet by a PO. Never had a ballast resistor, at least not in the coil location. Was running with the black coil as purchased,not great, however. Now running beautiful with the new blue and pertronics. Am I missing something here? Resistor located elsewhere that I am unaware of?
 
I believe 74's had a resistor wire intsead of a ballast coil - i recall references to such in other threads.
 
Coil

Damn,
Is this the resistor wire that I am looking at here? If so I will clean up and switch back to black. Part# for the red ?
000_0361.jpg

Learn every day and thanks.
 
There are others on the forum that can help you more than I, until they chime in, search "clear resistor wire" (no quotes) and there are 4 threads with usesful info for your 74. Since your engine is a conversion you may or may not have (or need) the original wire. If it is running well with current setup, perhaps leave well enough alone? I don't think you'd gain anything by adding a red coil and a ballast resistor over what you have now with the blue coil running well.
 
Coil

Yeah,
But it is possible that I am running less than pure, due to the resistor wire. Not giving her full on sparkage. I don't know about the rest, but I find my driving to be much more conservative than the past, for fear of other drivers, deer, elk in my district...So full on, not so much these days. More like a pleasure cruise, usually the bride in shotgun...you all know how this goes. Plug reads indicate as such. Slightly on the dark side for my satisfaction.
Since the coil replacement went on while I addressed numerous other issues, I now wonder.
Inclined to try the red, for s...'s and giggles.
 
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I relate to your wanting to give it a go. It's Bosch red coil # 00013. Make sure you determine your rsistor status, if you run full red coil with no ballast through the pertronix, it will likely fry the pertronix.
 
Yikes

Dilemma,
I changed the coil at the same time as the dist. upgrade. Yet before it ran on the black.
I was also doing an overhaul on the intake, injectors, all associated once stripped down to semi-bare. As before, the resistor is there to preserve the points, be it a in-line resistor or the old school ballast type. I am leaning towards the belief that the Pertronics is durable and will take voltage above and beyond what points will carry. That said, MSD et al.
 
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Black and red are the same nowadays. If you don't have the resistor wire than keep the blue coil, I doubt that there is any real difference.
 
black coil broken ballast resistor.

hello, does anyone know where i can get a ballast resistor for my 1971 2800cs? No one has one and I dont know where to start to get a good one.??. oh yea. i have the oriogonal black coil on my car. , should I just switch to the blue coil to bypass the reguator?. If so what do i do with the black and red wire that was going in to my ballast resistor and the green wire that was coming out of my oriogonal ballast resistor??., thank you. kip
 
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Still listed at BMW:

http://www.realoem.com/bmw/enUS/par....0CS&mg=12&sg=05&diagId=12_0953&q=12131353362


Or you can get a 1.8ohm one and a bosch red coil:

http://www.ebay.com/itm/NEW-Mercede...ash=item51ca31e787:g:4swAAOSw1ZBUtTT0&vxp=mtr

http://www.ebay.com/itm/Bosch-Ignit...ash=item51cca7d49a:g:KG8AAOSwNSxU7buh&vxp=mtr





virtualkip said:
hello, does anyone know where i can get a ballast resistor for my 1971 2800cs? No one has one and I dont know where to start to get a good one.??. oh yea. i have the oriogonal black coil on my car. , should I just switch to the blue coil to bypass the reguator?. If so what do i do with the black and red wire that was going in to my ballast resistor and the green wire that was coming out of my oriogonal ballast resistor??., thank you. kip
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