Hello All,
I installed a new aftermarket radio into the 78 last week.  Everything is working fine Except the power antenna.  Before I put the side console panels on I checked it and radio and antenna worked fine.
Put the side console on and radio works great but antenna doesn't.
Thought a connection might be the problem so got back in there and re-wired antenna connection a couple of different ways after a relay module and before it then back the way it was on the old radio (when it worked fine).
At this point I suspect a bad connection into the back of the new radio but wanted to ask if any of you have any other thoughts or suggestions.  Since you guys know everything about these cars if there is an answer it would be here, (I did go back several years on the forum but didn't find anything like this).
Thanks for any suggestions and or input.
Gofast

I'm a firm believer if you did something and something stopped working go undo it.   Now I say this with lots and lots of experience behind it.  I cannot count how many times I had to undue something.  Seriously I would take a good look at the new radio wiring diagram and make sure I have that figured out. The antenna circuit is not  hard to trace out.  You have your shop manual?

Thanks Guys,
I had already tried all those great suggestions (a couple of them twice just to be sure).
I am back to either a bad connection on the radio or bad antenna motor.  I am taking it into a shop tomorrow to see if they can trace the problem.
Thanks for the suggestions.
GoFast

The industry standard for the color of the power antenna control wire for an aftermarket radio is BLUE. This wire has 12v when the radio is on, and 0v when the radio is turned off. This blue wire should be spliced to the factory power antenna trigger wire, which was once connected to the back of the factory radio.

Found the problem, (actually the guy at the shop found it),  It was a short in how the original wiring harness had been wired up.  They had wired the blue antenna wire to the lighter and it had shorted out.  Best $30 I spent that day.
Thanks for all the suggestions.

At least you're better then me! I burnt up 3 antennas before we finally ditched  the old relay system and just ran the blue wire from the new radio to control the last antenna (I guess I shouldn't have said anything). The last one to burn up shorted out so bad that it destoyed the new Optima battery! Glad you got it working!