Stereo on 1990 Ford F-250

I installed a stereo, I've done this numerous times. But this time everytime I give it gas the stereo shorts out. I gave the truck a tune up and that's when I noticed it acting up. I thought it was the spark plugs so I switched to resistor plugs but nothing. I replaced the condenser and nothing. I grounded it at different places and nothing.

Asked by for the 1990 Ford F-250
When you say the radio shorts out do you mean it blows a fuse and you have to replace a fuse or the radio just stops working. It may be internal in the radio or a loose connection, try tugging at the wiring harness in various places and see if you can get the radio to stop working, trying to isolate where it is you have a bad connection.
I meant that the stereo is playing when the truck is idling but when I put it in gear and give it gas you can't hear it. When I'm going 20 m.p.h. or more with the foot on the gas pedal you can't hear anything, then I let my foot off of the gas pedal and the sound comes back.
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This could be resulting because your spark plug wires need to be replaced.
When I gave it a tune-up, I installed new Accel Performance wires, Bosch spark plugs at 34 gap, rotor, dist. cap, points at 17 gap and condenser all new, right after I noticed it acting up.