Can someone provide a link or describe the procedure in cleaning the contacts in my Rex coil. Is dielectric grease used after cleaning?

I have done it repeatedly, but just for general maintenance or to eliminate the coil as a suspect when I had a problem. Mine were not seriously corroded when I got them apart. From memory:

Remove ignition wire to dizzy and input wires from the bottom. Two 10mm bolts allow removing the coil from the car. Coil is held together by torx hedead screws (#25?), two of them, I think, in the corners. Once the box is apart there is an abvious strip of metal which contact the other side. I used fine sandpaper to clean this contact strip, and the other side where it contacts. Not being sure if it mattered but sure it couldn't hurt, I also cleaned up the contact points between the two halves of the box and where the box bolts to the car on the chance that it needs a good ground through that route. Reasembly is the reverse.

I did not use any electircal grease and I am always a little confused which kind to use when anyway. I think dielectric grease is an insulator and so is used when you have something like where the wiring harness connects at the bottom of the coil. There, you want to protect the contacts from the elements, but you do NOT want current to pass directly in between the wires through the grease. The other case is like where the coil to dizzy wire connects. There, you only have one wire, so you want a grease that will not only protect, but also conduct electricity and so give you an even more certain connection. I'm sure someone wiser than me can straighten me out on what the two kinds of grease are called.
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Andy in St. Paul - '91 745 227K mi, '91 745 210K, '90 744 194K, all Rex-Regina; '86 745 GLE M46 230K; past 240s

Once the box is apart there is an abvious strip of metal which contact the other side. I used fine sandpaper to clean this contact strip, and the other side where it contacts

Hi Andy,

I'm curious about this too see earlier post. I think the "box" as you call it is the "Ignition Amplifier" built into a heatsink. If so, it would compare to the Bosch "Power Stage", which is known to overheat when the "thermal grease" between its heatsink and body metal dries out after many years—reducing or blocking the needed heat dissipation to the body.

I also think this heat-related failure can be intermittent (coming on after X hours of running) or solid, and that there was a recent post where the REX ignition responded to a refreshing of that thermal grease. But so far I haven't removed the "box" myself to see what that "contact strip" looks like. I believe it's more than a ground contact (if that), and is more for heat transfer. If so, it probably would benefit from something like Radio Shack's "Heatsink Grease".

I'll be taking mine more fully apart soon to see for myself, in any case.
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Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.

Thanks, Bruce. I don't recall seeing any evidence of any grease having ever been in or on my units when I dismantled them. Based on the shape of the outside of this aluminum box, I'm sure there is a heat sink purpose to it. When you get it apart, the portion you can see is amazingly simple. I didn't describe it well, but it's obvious when you see it. What is in the sealed portion behind that "contact strip" is anybody's guess, but it does not appear sevicable (except by Art with a hacksaw).
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Andy in St. Paul - '91 745 227K mi, '91 745 210K, '90 744 194K, all Rex-Regina; '86 745 GLE M46 230K; past 240s