: hvac question

06-24-11, 04:44 AM
Hi all,

I havent been here for a while and ran into a problem you might help with.

I own a 1968 cadillac eldo with ac blowing cold , but blows out the vents only in park or neutral . when in D, or low the system blows out the floor and defrost vents...

could this the the neutral safety switch with a leak....

any brainstorming would be helpful....

thanks in advance


06-26-11, 07:21 PM
It's a vacuum leak, for sure. Probably on the rear of the control head in the dash, but check the line on the intake.

06-30-11, 09:15 PM
It probably is a vacuum leak. The system is designed to send vac to the idle speed up diaphragm on the carb in P/N. You might try pinching off the vac line to the P/N switch first. Check any other vac connections that are easily accessable too.