Vent Help
 

When I 1st got my Blazer almost a year ago, the vents worked fine....then all of a sudden they just stopped. No air whatsoever comes out of anything except the defrost and a little out of the floor vent. A friend said the entire dash would have to be taken off and the hoses checked to see if they have come loose....does that sound about right or is there an easier solution?

RE: Vent Help
 

Several possibilities but the ones that come to mind are the fan motor or fan motor switch being dead or the blend door being stuck in some weird position. I figure a good portion if not all of the dash would have to come out if these were the case, except for the switch which is quite easy to remove.

RE: Vent Help
 

check the vaccum lines. could be a broken line preventing the door to switchto the vents and stuff. can you hear the fan motor blowing at different speeds if you move the fan switch? also whats the year of the truck?

RE: Vent Help
 

The fan still blows out of the defrost vent and some on the floor...and yes, I can hear it change when I switch speeds....it's a 1997

RE: Vent Help
 

There is a ball-shaped plastic container under the driver's side rear of the hood (it is bolted to the hood itself) check to see if the vacuum hose has come off of it, if so just hook it back up to the port hole and start the engine...let it idle for a few minutes to build up a vacuum in the tank and it should fix it. If it isn't off of the tank, then check for any rotted vacuum hoses/connections under the hood first. Then check to see if you hear a very faint hissing in the dash with the engine running, put your ear next to the heater/ac control head (the fan/mode switches) and listen for the leak. If you hear a hiss sound...then your rotary vacuum valve (on the back of the mode selector switch) is leaking. Let me know what you find please.

RE: Vent Help
 

Thanks a bunch...I can't check it out right now cause my Blazer is in the shop....I have another post all about that issue if u wanna check it out lol...but as soon as I can get it back I'll look and see what I find

RE: Vent Help
 

Mine hissed for a while before the vents quit working(the hiss went away).

RE: Vent Help
 

I checked the ball-shaped plastic container & it looked like everything was where it should be, although I don't know a whole lot about things under the hood. I didn't see any hoses that looked rotten or hear any hissing, which I guess if I'm like DetroitMuscle, the hissing came before my vents went out lol

RE: Vent Help
 

The hissing came from the heater control switch thing, unit or box wtfever they call em. You really wont hear any hissing unless its a big leak, check your vacuum lines, they are small and black, see if they are cracked or crumbly, they are usually 5/32 in size and 7/32 in size, kinda like the washer fluid lines. Mine is a 92, but just the defrost and floor working is enough to keep my sweating in the winter.



By the way, if you were anything like me then I wouldnt be Me. its a vicious circle, sorry lol.

RE: Vent Help
 

No, those were the lines I looked at & they seemed fine....the defrost & floor vents working is good enough, I just can't stand to have something not working....like my back windshield wiper needs a new motor and that annoys me lol but I can't afford to do anything to it right now so I'll have to deal with it lol

RE: Vent Help
 

Have you checked amazon or eBay? I find alot of stuff cheap on there.

RE: Vent Help
 

Nah, it wouldn't matter lol I have zero dollars....I have 2 kids and that take all the money I get, unless it's a major vehicle emergency, it's a no-can-do lol

RE: Vent Help
 

Tell em to start chippin in or find a new source of food. Worked for my dad, Had my first job when I was 14. Oh, the vacuum lines are dirt cheap to replace and requires little to no brain cells to do. I replaced all mine for under 10 bucks. I think its under a buck or two a foot.

RE: Vent Help
 

lol my kids are 6 years old and 3 months old lol not quite ready for jobs just yet lol as far as I can see the hoses and everything look ok....I dunno what the prob is, oh well lol

RE: Vent Help
 

lastcoupe nailed the problem on the head.

Look for the vacuum line on the back side of the intake manifold. This is where the vacuum comes from. Look on the passengers side, next to teh distriburator. It will split and go to the t-case, to the black ball, and to the dash via a hole in teh firewall in the middle somewhere. If you have a leak in any of those vacuum hoses, your vents wont work, your 4x4 wont engage the front axle, you may have performance issues (like a poor running engine). If your truck is in the shop for poor performance, hestitation, etc. They may just fix your vent problem too.

RE: Vent Help
 

If that is the case, will removing that vacuum system including lines work? I am chaning to the twist lock for the 4x4, but If i can get rid of all the crap Id rather do that then just disconnect and leave in place.

How exactly do you replace that dash line? R&R the dash cap?