Yes, you can change the switch on your late model without losing the freon. The models with a trinary switch such as yours have a valve behind the switch that closes when the switch is removed.

Mark

Michael Sullivan wrote:
> Can I take the pressure switch off the high pressure line in the DS side
> rear D pillar and pop the new one in and NOT lose all the freon? Thanks.
> Michael in San Antonio
> 91GL Weekender AT 2.1L 'Gringo'
>