The lights go out

When I turn the lights on , the dash lights go out on my 1988 k1500 silverado

@ironhorsediver

Do you have a dimmer knob for the cluster?

Do they blow the fuse or just not light up? Either way I think you have a switch problem.

no, it does not blow the fuse, I will have to check the switch
thanks

@ironhorsediver

What about that dimmer?

On many cars, unless the dimmer is at maximum setting, the cluster illumination will be very dim when turning on the lights