I know that civilian passenger car production was halted from 1942-45 for the war, was civilian radio production suspended as well?

Yes.
Phil

Any '42 model radios came off the assembly line before production was halted, or were made from '42 leftovers. Case in point, the Philco car radios that were retrofitted into leftover console and chairside cabinets.

Production was stopped in Spring 1942 and resumed in Fall 1945.

So how did Echophone keep going? Waiver for "morale" radios?

Morale radio were made by other companies, too. Some were Scott, Crosley and Templetone. This was done under military contracts- for use by military personnel. One civilian item, that I know of, which remained in production during WWII was (vacuum tube) hearing aids by Zenith. Limited numbers of vacuum tubes were also manufactured for maintenance of civilian radio sets since broadcasting was important for keeping the public informed on current events.

I know you couldn't even buy a new radio during the war.
My mom told me they were still using an older set from
the late 20s when the war hit. They wanted a new one and
couldn't get one at all.
As soon as the war was over and production started up she
bought the first thing that was available and it just happened
to be a Westinghouse Little Jewell. I'm proud to have it in my
collection.
The guy at the store where she bought it told her she should
wait as something new was coming, but wanted a new right then.
Of course the new thing that was coming was FM. It's a good
thing she didn't wait because it was more than 10 years before
the same town where she lived got an FM station.

The earlier answers are all correct. If I might expand a bit, the controlling government authority was the War Production Board, or WPB. They issued orders concerning literally every consumer good. One of them ordered the stop of production of 349 tube types for civilian use, effective April 24, 1942. They gave an exception, for the case of existing lend-lease contracts. I have never seen or heard of a tube or radio that was actually made or marked for such use. Another order stopped the civilian radio production. It applied to most manufacturers by April 22, although some had changed to war production earlier, and about 25 smaller manufacturers were allowed to continue another one to six weeks.