Idiot lights come half-on during acceleration

Here's an odd one for the group. My idiot lights are coming on when I
accelerate fast. Not when I slowly step on the gas, and total speed
doesn't seem to matter, just acceleration. If the lights go on, they
stay on until I step off the gas.

By "idiot lights" I mean the danger indicators - battery charge, brake
failure, brake lights, and "service." They don't go on full, just
about halfway. Oil light doesn't go on.

I am driving a Volvo 240 DL, 1988 model.

Any insight to this problem? And is it serious, or just annoying?

 

Check the ground strap between the the engine and the firewall, it can cause
a problem like this. It's also worth checking the condition and tension of
the alternator belt.

 

Just dealt with the same thing in my 82 240. i removed the alt. and
cleaned EVERY electrical connection. No more glowing. I also cleaned
any under-hood electrical connection that seemed suspect. I tend to
think it is a grounding problem that got cured when i messed with the
alt. I have trouble believing that a weak alt. or bad hook up
connection would activate all the idiot lights. then again, i've
learned to believe all things are possible when it comes to stupid
electrical problems on my 240.

 

On most cars, failure of the alternator will cause all the idiot lights to
come on, just as they do when you turn on the key without the engine
running. It's how you test the lights.