Headlights flicker and radio cuts out when going over bumps

[bennylava]

Hi all, I wanted to stop by and ask about an electrical gremlin I'm having in my truck. It's an 87 model with the Tbi 350 and 700r4 transmission, 2WD. Every time I go over a bump, the headlights seem to flicker a bit, and the radio cuts out.

It's a modern radio so when it loses power it restarts, which takes a few seconds. And that should help with finding the problem. Cause you'd just wiggle stuff until you hear the radio cut out.

But despite all the wiggling and jiggling of wires under the hood, I can't make the radio cut out while the truck is in my garage. For some reason, it wants to go over a bump in the road before it will reproduce the problem. So I must be doing it wrong.

Is there someplace else I should check?

I've recently checked all the grounds because I had to replace one to get the starter to work. So I know the main ground to the frame is good, and so is the one that is on top of the engine. If anyone knows of other more obscure ground wire connections, I'll check those too. Thank you