I have a problem with my wiring I think, It finally came time to start my 27 coupe after a 20 year restoration project(raised my 4 children in between)Turned the ignition switch and my coils weren't buzzing and the switch started smoking, ok something wrong, I figure bad switch or I put it together wrong so I tried to put direct power to coils by running power directly to post on bottom of coil box this started to ARC. I double and tripled checked the wiring and its right I went on suppliers site and it said that I might have to modify the coil box on a 26 or 27 but I cant figure out how. I figured the box is grounded to the block, power runs through bottom from switch and then communicator on tops then fires plugs from middles of buzzer coils. I am stuck any thoughts on what I'm doing wrong..
When you powered the coil box did you remove the wire that normally feeds it from the wire loom? In other words did you disconnect it from the car? If you didn't take it off and it arcs your problem is probably elsewhere. If you removed it and powered that terminal and it arced your problem is in the box.
I didn't disconnect it but the switch was off so it shouldn't have had power I thought
Once you applied power to the connection on the coil box it's feeding back to the switch and short.
So you left the wire connected from the loom. There was no power there until you connected an external powered wire and you saw an arc. Correct? So either that wire going to the switch is shorted to ground (doesn't show a short unless it's powered) or it's in the box. You need to disconnect that wire and power the box again externally. No arc? it's the wire. Arc? it's the box. I realise you said the switch was smoking but it could be the wire itself shorting to ground and not the switch itself.
Charlie thanks for the response I went to the garage and disconnected the wire to the bottom of the coil box as you mentioned then I applied direct power to it and it is still arcing. so you mentioned it should now be the box, I did replace all contacts from old box because it had caught fire once along the years do you think I put it together wrong I actually rebuilt it exactly like it was.
Pull the coils if their still there and try it again as it could possibly be one of them somehow. If it still shows a short it's most likely the wire that goes from the outside terminal to the feed strip on the bottom of the box. It's internal & is a cr*p setup to begin with. You're getting closer. At least it doesn't appear to be the switch or car wiring.
You wrote; "...wire to the bottom of the coil box as you mentioned then I applied direct power to it and it is still arcing."
Little can go wrong in the '26-'27 engine mount coil box at the bottom hot terminal strip. That strip is isolated, and the contact terminal goes just to it.
The firewall mount box is a different animal with a solid core insulated wire going in a groove and it can contact the metal case.
Could be you got some of the other coil box terminals with grounds. The coil box innards and terminal strip or contacts need to be isolated from any grounds.
went outside took the coils out and it is still arcing Charlie wrote it now should be in the box but now looking at Dan's pictures I think it is in the box because the bottom strip on mine goes all the way to the ends so the rivets are also holding the strip down at the end so I might be grounding and supplying power at the same time that would make sense with all the issues that I'm describing
You might want to check the generator cutout. When Martynn Vowell and I rewired Derrick Pang's Runabout we discovered that the cutout screw was too long and grounding out the Battery and causing smoke from the ignition . Two or three washers under the screws head left enough space to keep it from grouping out.