The headlights on my '75 would only pop up with the secondary control under the dash, so I replaced the headlight switch.  Now they will still not open with the headlight switch, but if I use the under dash control to open them, (then push this control back in with the headlight switch pulled out), they will stay open, and close when I push the headlight switch back in.

Hi Bill, Yes, this does sound kinda strange. Just to throw something out there! Did you replace the vacuum hoses on the light switch correctly. One of the hoses ( at least on the 73) has a blue stripe on it and the other is plain black. They need to be installed on the correct light switch ports. Sorry, but I can't remember which way they went. Check your AIM. Also, some of the repro switches have been known to be faulty. They are all made in Tawaiin. Regards, Jim

That was it!  I switched the vacuum lines (putting the blue stripe towards the driver) and they now work!