blower works...
Thread Starter
Le Mans Master
Joined: Jul 2003
Posts: 7,501
Likes: 1
From: Maine
blower works...
only blowing air outta the floor vents... the switch works lo-hi...but no defroster or dash vents... only blows out of the floor vents... switch or vacuum? where to start....
Race Director
Joined: Apr 1999
Posts: 11,520
Likes: 13
From: CORVETTE 77 385 C.I. TEXAS
I wrote this up awhile back for this problem & many have used it to fix.
On at least later C3 the problem is that heater is the default position (no vac. or vac. leak) due to being designed in the north. Vent should be default. Very safe bet the problem is 1 OR 2:
1) The vac. line from engine may be damaged from heat - a small plastic tube that goes in pass. side of dist. below the hood alarm switch into wiper valley. Replacing most of engine side w/ hose will normally fix. OR
2) The vac. switch itself is not switching due to vac. leak as the usually plastic rivet is not holding the 2 main switch parts together well. Besides replacing, it is also possible to tighten this &/or disassemble to lube w/ a thin layer of white lithium grease to fix. Try pressing the 2 halves of the switch together to test in A/C or VENT w/ engine running.
3) If you have a heater, the small vac. tube to heater hose valve under hood may be damaged from heat & need replacing. Block w/o heater.
PS The design problem comment is not intended to be offensive to any of our northern friends.
On at least later C3 the problem is that heater is the default position (no vac. or vac. leak) due to being designed in the north. Vent should be default. Very safe bet the problem is 1 OR 2:
1) The vac. line from engine may be damaged from heat - a small plastic tube that goes in pass. side of dist. below the hood alarm switch into wiper valley. Replacing most of engine side w/ hose will normally fix. OR
2) The vac. switch itself is not switching due to vac. leak as the usually plastic rivet is not holding the 2 main switch parts together well. Besides replacing, it is also possible to tighten this &/or disassemble to lube w/ a thin layer of white lithium grease to fix. Try pressing the 2 halves of the switch together to test in A/C or VENT w/ engine running.
3) If you have a heater, the small vac. tube to heater hose valve under hood may be damaged from heat & need replacing. Block w/o heater.
PS The design problem comment is not intended to be offensive to any of our northern friends.
