alright so 88 Gl ea82

I have had problems with the fan going out before and replaced it and currently 1 and 2 are now broke which is tolerable. however within the past few months I have had trouble toggling between vent and defrost and the like and it would be delayed responsive. now it is stuck on vent and when I push the buttons to change it nothing happens.

Any thoughts on what to check on for fixin this??

Thanks!

Changes in where/what is allowing air to flow from Heater-A/C system is vacuum controlled.

 

On your '88 there's a vac line off the PS of the intake manifold that goes to a soup can sized White canister mounted to the PS strut tower. That is a vacuum resevoir.

Check the hose going to it for any cracks/splits, as that is most likely the culprit. Could be something after the canister, but usually the hose from manifold is issue.

 

Can of carb cleaner, lightly sprayed at vac lines and hoses, will tell where problem is. You will notice a change in engine RPM's when leak is found.

^^ Every time I replace an axle, or fix anything on that side of the car under the hood. I end up pulling off the side of the road and reconnecting that damn vacuum line. They could have made it longer and actually routed it in a sensible way...

 

I vote for that being the problem, too.

The heater blower not working in 1 & 2 could be the blower fan resistor in the fan housing behind the glovebox.

My 87 gl had the same problem with vent/heat/defrost. Turned out to be the black plastic had cracked where it mounts to the switch/control body with screws. Bought one from a fleabay seller in S. Dakota - it was fubar too:mad:

Direct sun is brutal on these plastic parts.

Finally found a good one at the local PAP. Replaced that & the resistor then everything worked correctly.

Just remember to mark the hoses on the back &/or do them one at a time.

Does your engine idle normally but shake violently? Or can you hear a hiss coming from your motor? I just had the same problem but I found a bad leak where the dude above me said to spray carb cleaner

ok I'll check out the vac lines. thanks!

hahahahahh well I feel dumb....

But hey thank the lord for free fixes right??

one of the vac hoses came disconnected.

Thanks guys!!

Trust me lol I felt dumb when I found mine, you'll probably get better MPGs now too

So... if the defroster button won't stay pushed it would it imply a leak in the vacuum line connecting it right behind it? everything else works great.