Distributor Condensor Coil Replacement Question

[morglan]

I've been having trouble w/ my 82 Silverado starting on cold mornings (0 F). It gets gas, but isn't firing. It seems to be fine once the sun warms it up for awhile, but I suppose that could be coincidence.

I did the usual first--replaced the cap & rotor, soaked it in WD-40. Ran fine for a couple weeks.

Last weekend, it got cold again and wouldn't start. I opened up the distributor, and "massaged" the rotor and wiped out the inside of the cap. It started. The next morning when it wouldn't start, I tried the same thing with no luck.

This morning, I swapped out the condensor coil (or whatever that "U" shaped plastic thing with the coil at one end and a male electrical end at the other is called) and it immediately fired, and ran with no problems.

Here's my question--the male end on the old (presumable bad) piece had three prongs, and the "new" one only has two. I just attached the connector and left the extra prong out, then put everything back together. Is this a problem? What is the third prong for? (Each prong was marked with a letter--the one I didn't use was marked "H".)

Thanks.