Blower won't work on high.

Discussion in 'The Big Chill' started by kutison, Apr 27, 2016.

  1. kutison

    kutison New Member

    Hi everyone, new guy who has never had a reason to pull a dash before.

    I've been working on my HVAC system for my 71 Riviera. I just got the heater core installed today, but I'm got a ways to go.
    My blower won't function on high and none of my temperature doors actuate. probably an issue with the vacuum system.
    But from what I can see, the high speed setting for the blower is routed through the climate control panel that manipulates the temp doors as well.

    I test for vacuum pressure right before the climate switches with the engine running right? I think if that is replaced it should fix my blowers problem.


    On an unrelated note. This was my grandpa's car, and I found his old zippo in the plenum when i installed the heater core.

    Thanks for advice and I'm glad i found this site.
     
  2. STAGE III

    STAGE III Lost Experimental 455-4 Bolt Main Block.

    Welcove to V-8 Buick!

    Try this info another member posted, and always look at the bottom of the page that matches common links that sometimes bail ya out. Good luck!

    There is only the one fuse box - is the stock radio still there or has some messed with wiring ? radio and other things (think heater control) ground at the radio bracket so if its been messed with or ground not connected/bad.

    The 71 Riviera electrical diagrams and schematics are in the boattail specific library at http://boattail-riviera-by-buick.com/library/documents/documents.php

    full chassis manual http://fullsizebuickregistries.boattail-riviera-by-buick.com/Library/Common/1960s-70s/documents/index.php?model=%27.$modellibrary.%27

    ---------- Post added at 08:44 AM ---------- Previous post was at 08:24 AM ----------

    Originally Posted by robs71redriv
    There is only the one fuse box - is the stock radio still there or has some messed with wiring ? radio and other things (think heater control) ground at the radio bracket so if its been messed with or ground not connected/bad.
     
  3. SteeveeDee

    SteeveeDee Orange Acres

    IIRC, GM in those years had a super heat thermal limiter switch for the AC. It is (usually) located on the fender by the AC compressor. It is really a fuse that will blow if the AC system is low on refrigerant. I dimly recall that high blower will not work if the thermal limiter is popped. It's easy to tell with an ohmmeter. It is black, has three prongs on it and is about the size of two joints on your pinky finger. Just follow the power wires to the AC back through the harness, and you will find it.
     
  4. CJay

    CJay Supercar owner Staff Member

    Thermal limiters....I remember they would hang in the aisle of the auto parts store on a blister pack. Popular item back in the day.

    This isn't automatic climate control is it?
     
  5. Brad Conley

    Brad Conley RIP Staff Member

  6. SteeveeDee

    SteeveeDee Orange Acres

    Low speed blower doesn't work until some temp is reached. Not the same as the high blower speed not running, but then I don't know everything. I'll put this info in my short-term memory where it will pretty much evaporate, soon. :Dou:
     
  7. kutison

    kutison New Member

    not a lot of progress today

    Figuring I have a bad ground somewhere, I started piecing my dash back together. Looks like the ground was missing from the climate control bracket, I saw arcing through my headlight switch to the lower dash. I don't have a stereo bracket. it was just ziptied to the vent above it and secured to the dash.

    I am willing to bet the blower issue is one of the relays over by the AC box on the firewall. I tried checking them and they cracked and crumbled. I doubt the AC has been serviced for a long while either.

    no progress on the blend doors either.
     
  8. flynbuick

    flynbuick Guest

    Check the high speed relay on the firewall and the terminal connections to it which can melt.
     
  9. kutison

    kutison New Member

    Good news is I got the vacuum issue fixed and the blend doors work again. Looks like someone had capped off one side of a T connector and disconnected the hose from the black plastic air reservoir near the passenger side firewall which is supposed to be mounted, but was tucked behind the engine block.

    The grounding strap from the firewall to the engine block was broken and disconnected from the block. Would that cause electrolysis in the heater core? I don't know much about electrolysis, but the old core was pretty messed up.

    I also don't have a coolant temp sensor installed, and that lead was also disconnected.

    The relay connections were pretty corroded, I cleaned the off, but I'm cant be sure that fixed the issue yet until the strap is on there.

    I'm probably gonna have to find a pay a small child to install that stuff, i got about 4 inches between the firewall and heads.
     
  10. SteeveeDee

    SteeveeDee Orange Acres

    Heater cores can corrode, anyway. There has to be antifreeze or some other corrosion-minimizing chemical in the cooling system. But you need that ground strap anyway, for sure.
     

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