what is it and what does it do?

Post your E12 technical questions and comments here. Please, no off-topic posts.

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under the radar
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Location: half moon bay CA

what is it and what does it do?

Post by under the radar »

i'm asking about the white twin cylinders with three spade terminals screwed to the inner fender right next to the ignition control box. mine gets very hot, is this normal?
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Mike W.
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Post by Mike W. »

That's the ballast resistor for the ignition. Getting hot is normal, that's what a resistor does, disapates heat. It's function is to have higher voltage going to the ignition/coil when cranking and voltage is reduced due to the starter load, then drop voltage during normal running to give good coil life. E12 era electronic igniton is pretty hot, I'm surprised they used it but they did. It's almost a relic from an earlier era, the points and condenser era.
Mike W.



1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
under the radar
Posts: 106
Joined: Fri Jan 09, 2009 12:39 am
Location: half moon bay CA

Post by under the radar »

thanks mike. i should've known that is supposed to be hot being that is encased in aluminum as a heat sync. i'm just chasing down any leads on my '79's choking/bogging problem.
the early nineties called. they want their awesome back

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T.Hanson
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Post by T.Hanson »

http://www.secondchancegarage.com/public/122.cfm

Google searching is so much easier than riding my bike to the library.
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