Federal Interceptor PA-20A 2D problems

[Lundy]

Looking for some help. I have a PA-20A 2D from 1969 that I'm fixing up. I've replaced all four transistors and the siren is fully functional. The only issue I have is when I select the WAIL position, the siren doesn't automatically engage. It'll stay silent before winding up and the wail tone does not loop. It rises, falls all the way down and goes quiet before rising back up again. Yelp and HI-LO both function fine. As does the MANUAL siren.

 

[shues]

https://www.fedsig.com/resource-document/file/8018

How similar is your 2D to the 2E?

 

[Wailer]

https://www.fedsig.com/resource-document/file/8018

How similar is your 2D to the 2E?

The 2D and 2E have completely different circuits and also sound different.

2D has deep slow rising and falling wail and yelp tones.

2E has high pitched fast rising / slow falling wail and yelp tones.

I checked my 2D manual and the problem is not listed in the troubleshooting chart. I wonder if it might be a weak electrical connection somewhere if the siren tones all seem to be working.