Mike, like I said try checking all wiring behind the radio, and if that ain't it I have no clue...except maybe they did something with the electric when doing the engine swap-no accusations - just lookin at the variables...

Did they swap anything, change connections/sources in fuse box? Maybe did some arc welding/plasma cutting with radio in car and battery connected? Could have fried the board in the radio...

Of course there could be a hairline crack in the main board of the radio, seen it happen 2-3 times, and it only begins to separate and cause trouble when the radio heats up.

Advice-trade it in as a core unit on a new one, head for the junk yard and have a look see for a match, or break down and buy that Sony ES...by the way the amp, if installed, can be uses with most non ES units, just have a male DIN to RCA made up and runa jumper to the remote antenna signal wire as an amp signal on/off.

That's all I can tell ya! If you want me to do a diagram and fax it to ya just email me a fax number.