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Recently my directional controls (floor, center, combo, defrost) don't seem to be working - everything is stuck on defrost with some being directed to the floor.
Has anyone experienced this problem before? Pushing the buttons causes the light over the button to come on, but nothing is happening.
Does the whole control module have to be replaced or are there still vaccuum controls up under the dash - I must plead ignorance when it comes to the mechanics of the climate control electro-mechanical system.
Recently my directional controls (floor, center, combo, defrost) don't seem to be working - everything is stuck on defrost with some being directed to the floor.
Has anyone experienced this problem before? Pushing the buttons causes the light over the button to come on, but nothing is happening.
Does the whole control module have to be replaced or are there still vaccuum controls up under the dash - I must plead ignorance when it comes to the mechanics of the climate control electro-mechanical system.
It is going into the default settings. This is usually caused by broken vacuum fitting under the passenger side fuel rail.
Very easy. Just lift off the passenger side fuel rail cover (just lift, it 'pops' off). Vac fittings are about middle of the intake manifold and the one most often broken is sorta an F shape with two lines coming off of it. One line goes to the AC/Heat controls and other one to the FRP.
Bad nes is that fitting is dealer only, good news is it is cheap. The engine heat just gets to it over time and the plastic gets brittle and breaks.
Thanks all for the quick response - I was afraid it was the climate control unit itself - was checking prices - just in case - $175.00 to $200.00 - YIKES!
Very easy. Just lift off the passenger side fuel rail cover (just lift, it 'pops' off). Vac fittings are about middle of the intake manifold and the one most often broken is sorta an F shape with two lines coming off of it. One line goes to the AC/Heat controls and other one to the FRP.
Bad nes is that fitting is dealer only, good news is it is cheap. The engine heat just gets to it over time and the plastic gets brittle and breaks.
Thanks again for the information - that valve is called a "Check Valve" cost all of $6.50 at the dealership. When I touched it - it just fell apart - It's actually shaped more like a little "pot" with a funnel top - the "Funnel Top" had a hole in it - so it was sucking outside air - and when I disconnected the lines (3) - the top fell off and one of the tube lines broke. It was brittle as heck. Put the new one on and every thing is back to normal!. I was afraid I would have to be ripping the dash apart to fix it!
I was having trouble with my 95 system also. Was ready to buy a new head unit for big bucks when I read this thread. I replaced the vacuum fitting today and moments later the function and lighting of the climate control was restored! You guys are awesome in my books!
Guys with Vette's seem to be able to figure out anything.
All C4s have a vacuum check valve. On L98s it's next to the distributor on the driver's side. On LT1s it's under the passenger side fuel rail cover. They look like this (L98, then LT1):
Actually, not all LT cars look like the bottom. That's the newer style GM one. Both my '96s had the top style. You can get ones that look like the original from the Help section in auto parts stores.
Actually, not all LT cars look like the bottom. That's the newer style GM one. Both my '96s had the top style. You can get ones that look like the original from the Help section in auto parts stores.
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They both function the same way, so I don't think it matters what they look like. I don't know if the hose barbs are the same size (or if that matters -- maybe they're close enough).
Just for reference, I bought one of the L98 types at AutoZone for $3.95.