[MrArt2u]

I’m trying to use the factory AM/FM in my ‘64 Bonneville for the first time in 20+ years that I’ve owned the car and I’ve run in to some issues. . I get nothing if I plug the yellow 12v wire from the dash harness in to the ‘12v in” on the bottom of the radio unit. (the plug that has 12v and spkr connections)

The radio only works if I plug the yellow 12 volt wire from the dash harness in to the blue pigtail that comes off the side of the unit, which, I believe, is meant to send power to the reverb unit when the radio is on. So I get radio but no reverb.

Does anyone have a PDF of the schematics or SAMS photofact for this radio? (I think it’s a 984078) I’d love to clean, recap it and get the reverb working.
Thanks!

[Jack Gifford]

Try this:
http://www.vintagemanuals.com

[MrArt2u]

Thanks Jack, that’s a great resource but I didn’t find what I was looking for there.

[Bill Hanlon]

SAMs is still around, including downloading .PDF files from their website. They have your part number.

Look here: https://www.samswebsite.com/en/photo...x/model/984078

[MrArt2u]

Thank you, Bill, for pointing me in the right direction. I had no idea SAMs was still around. I saw their offerings and decided I wanted an original, not a copy (I restore old pinball and arcade computer boards, I hate struggling to read bad copies!) so I found original SAMs AR-24 (has ‘64 am/fm schematics) and AR-22 (Has ‘64 Reverb schematics) for $4 a pop on ePay.
I’ll likely put together an electrolytic capacitor shopping list in the near future. When I do, I’ll post it here.
Thanks for the help.

[MrArt2u]

Posting this information for anyone in the future searching for am/fm troubleshooting. My radio would not work when power was applied to the 12v in but it would work when it was applied to the blue pigtail wire meant to feed 12v to the optional reverb unit, though it would always be on when the key was on.
I traced the problem to a faulty on/off switch on the three stack volume/tone/on-off potentiometer. I removed and disassembled the pot and found nothing wrong mechanically though the contact points of the on/off portion were heavily tarnished. This particular section of the pot was difficult to disassemble so I soaked it overnight in 91% isopropyl alcohol and tested it in the morning with my meter. It worked, so I further cleaned it with Deoxit. and reassembled the pot and the radio. It is now working fine.
If you encounter this problem, you may not have to disassemble the potentiometer. Once you remove it, you can soak the bottom third of the stack in cleaner overnight and it may be sufficient. I saw no evidence of any grease in that section so I did not lubricate it on reassembly. Removing the pot from the radio chassis requires desoldering 6 wires.
If your volume or tone are scratchy, you may want to open it up to clean, they are sturdy CTS brand pots (as used on vintage guitars ;-) ) so they’re user serviceable and pretty well documented online.
I hope this helps someone someday. And thank you for using the search function of this forum.