I have replaced the reostat control for the brightness of the dash and switch lights. I read someone just bypassed the switch so you can't dim the lights.....who cares.
has anyone done this and can tell me how to? All switches,and dash bulbs are good.
Also, rear defrost button will not stay on. It's new but won't remain in the engaged position.

Ah, finally.. issues I can help with!

First, the defroster. Does it engage for a few seconds, and then turn off? If you hold it down, does it defrost / defog the back window? If so, it's probably the same problem I had.. your defroster relay. The relay is located under the speaker, on the driver's side.

The dash lights.. I need more info on. Are you trying to make it unable to dim (full bright, all the time), or are the dash lights not coming on at all? If they aren't coming on, you may want to pull your dash, grab a multimeter, and start checking for continuity on the circuit board. More than likely, one of your solder tracks got severed, causing the light malfunction. Either that, or you have a bad ground on the cluster.

Elaborate on the symptoms, and I'll be able to try and pinpoint the problem.

The rear defog switch is a momentary switch, meaning after being depressed it returns to the center position. It does not "lock" like the antenna switch. Once pushed, it should illuminate to verify current to the rear glass. If it doesn't light up I suspect the relay mentioned above.