how do i fix my 91 chrysler dynasty heater ?

Thanks Jeff,I blew crude out of the vacuum check valve and it stared working OK.The heater functions the way it should now-great this cold weather here in ontario, canada.

Ernie Moorhead
February 2007

You most likely need a vacuum check valve installed or replaced. It is located by the brake booster where the small plastic line tee's off. It stops the vacuum from bleeding off during heavy acceleration. Your vents are working like they should under a vacuum depletion condition(wide open throttle). Some Chrysler's left the factory withouy this valve. I recall a TSB to install one back then. It should be 1" Diameter, 2" tall black plastic with male nipples on each end. Good Luck

Jeff Fisk
February 2007

I had the resitor replaced and 1,2,3 speeds of the blower now work but the air flow problem remains

Ernie Moorhead
February 2007