I'm having ventilation issue. When I switch on the air in my cutlass (be it a/c or just to have air circulating), it will not work on high. I get air flow through the vents on the 3 lower settings, but as soon as I set the vertical switch it to "high", I get nothing.

Any ideas?

 

Yes, lots of them.

This question comes up nearly every week, with the most recent less than a week ago, if I recall.

You need to use the Search function and read any of the probably 20 or 30 threads on this exact issue, or look at the wiring diagram in the A/C section of your Chassis Service Manual.

The problem is either in the heavy wire from the horn relay to the High-Speed fan relay, in the inline 30A fuse that's in this wire, or in the High-Speed relay itself, with a remote possibility of a bad contact in the fan speed switch.

- Eric

 

Thanks. I found a site with the chassis service manual. I will start tracing wires after I get off of work.