it sure does point to it with that being the only change especially a back to back change which it sounds like this orange to chrome box swap was. I would hold off tho till the ballast arrives. Good things come to all who are patient (at least that's what I get told!), on a regular basis.

Also the connector at the base of the steering column. The one that comes from the ignition switch. My 70 just had the same problem. I took the blue and the red from the connector and soldered the wires together. When it dies do you loose power to everything? Mine did and itt was the red wire causing the problem

I hadn't thought of this. Where exactly is this? Is this that big connector with about 20 wires in it, or is this something else lower down, maybe towards the floor?

Thanks.

It is a flat plug with 6 or 8 wires near the floor. It comes from the ignition switch. The connector may be tucked up on top of the column.

I bet orange box is quitting.

I think these guys nailed it immediately. I've had a similar problem when my ignition box was going bad. Sometimes you can even see they look a little gooey/melted on the back when they're going bad, but it's not always visible like that.

I"m skipping ahead here, but dan9 is onto something. If your car goes COMPLETELY dead, there's a blue wire under the hood (where the factory fusible link is located) that is the main power wire going into the bulkhead disconnect. And as I think dan9 is talking about, I've had issues with connections at the two plugs at the bottom of the steering column and the slightly larger plug (flat, 8 or so pins), has the main power going through it. Sometimes a teeny tiny screwdriver pushing the metal connecters together from both sides (slipping the tiny screwdriver inside the plastic plug hole, next to each wire, pushing forward on the metal connector itself) can fix issues where whole sections of electrical (eg ignition) just go dead all at once, but "usually" those bad connections don't fix themselves by sitting & cooling off for a few minutes.

The back of my orange box was pretty soft. I could easily make indentations in it with my fingers when it was cold.

I agree

With him switching ECU s back and forth , could of created a cleaner ground by loosening and tightening bolts / screws

Ground wire to bolt right on ECU , even if temporary would bee a good solution / test - Would eliminate any grounding issues through that bracket itself

Remove the resistor and see if the backside wire is exposed - Some are not

You can usually see where they are broken if exposed

Last one I had do that the guy painted up the coil all pretty, new decal on it... it was a ford coil. Car would run quit, cool down a few minutes, then restart. Hot days were the worst, new mopar coil fixed it, orange box is still on it.

Well, I replaced the orange box and so far, so good. I've driven the car about 40 miles with no issues!

Awesome!