1989 S-10 Blazer has hissing dash

[tak927]

I have a problem with my 1989 S-10 blazer with a hissing noise behind the climate control levers. First of all, I just had an uncle change the heater core for me. (Second time for this blazer.) Now I have the hissing behind the control levers and the air only blows out the top dash(defrost) and floor vents. None from the front dash. No matter what you choose- vent, heat, air or defrost. Does a vacuum line run through the heater core area where it might be pinched? Or do I have a new problem with a bad climate control device? If it is the climate control, how in the world do you change it? I got as far as taking out the two dash screws below it and the control only pulled out an inch or two. I thought maybe a vacuum line came loose in that area but it is difficult to see behind the dash. Thanks for any help!!!!!

[DaveLance]

The vents are controlled by a vacuum line. It sounds like the line was pinched when the dash was put back in. It's also possible that the line was simply pulled off of the back of the controls. The only way (that I know of) to find it is too take the dash out again and track the leak down. I'm not that familiar with 89's, so I can't offer any other hints and tips.

[jsgold]

Your controls should be all vacuum controlled, so you may have pulled off a line somewhere under the dash. I have seen this mentioned before in either this forum or Blazer forum. Try a search. I am pretty sure there is a device (maybe a servo???) under the dash that you should be able to see. Sorry not more help.

[BlazerLT]

vacuum line was pinched or partially pulled off of the controls.

[tak927]

Thanks for the help!! Seems to make sense the problem is behind the controls since that's where I hear the leak. Any help on getting the controls pulled out? Thanks!

[JA no Y]

Originally Posted by tak927

Thanks for the help!! Seems to make sense the problem is behind the controls since that's where I hear the leak. Any help on getting the controls pulled out? Thanks!

Just be carefull not to pull any more vacuum lines loose