AC positions and fan HI not working
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Joined: Sep 2011
Posts: 316
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From: Birmingham, Alabama!!!
Car: 1988 Iroc-Z
Engine: 350 TPI; Stock internals
Transmission: 700r4; TCI-CPVB; BW Hi-Frition
Axle/Gears: 4th gen 7.5 w/ 3:42 gear
AC positions and fan HI not working
Ok, I'm having some issues with the AC panel:
HI on the fan switch isnt working (the rest are)...
AC compressor isnt kicking at all
When I move from Defrost to Vent (or where ever), the selector doesn't move the flaps at all...
Thoughts?
HI on the fan switch isnt working (the rest are)...
AC compressor isnt kicking at all
When I move from Defrost to Vent (or where ever), the selector doesn't move the flaps at all...
Thoughts?
Supreme Member
Joined: Jan 2006
Posts: 3,341
Likes: 10
From: Mooresville NC
Car: LOWERED ♦ CRIMSON METALFLAKE
Engine: ► 400 KUBES ◄
Transmission: 765R4
Axle/Gears: EATON POSI 4.56
AC Anxiety
The hi speed is controlled by a relay.
To test the relay coil when it’s still in the car, apply 12 volts to pin D orange wire.
If it’s good you will hear it ··CLICK··.
Also, if the rest of the relay and blower circuit is good, the blower will come on.
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
AC:
Using a voltmeter or test light (the type for testing for voltage, not a continuity tester) probe the light green wire on the pressure cycling switch located on the accumulator (the silver can on the firewall).
Is there power there when the key is in the RUN position and the AC controls are set to AC?
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Flap Trap:
The most likely cause of the blend doors not working is an interruption of vacuum to the Mode Selector.
You can remove the HVAC panel to see if the vac hose is still connected, if the vac hose pull air while the engine is running, and if not trace it back to the pinch or break.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Spin Me This Week . . . I’ll Spin You Next Week
.
To test the relay coil when it’s still in the car, apply 12 volts to pin D orange wire.
If it’s good you will hear it ··CLICK··.
Also, if the rest of the relay and blower circuit is good, the blower will come on.
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
AC:
Using a voltmeter or test light (the type for testing for voltage, not a continuity tester) probe the light green wire on the pressure cycling switch located on the accumulator (the silver can on the firewall).
Is there power there when the key is in the RUN position and the AC controls are set to AC?
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Flap Trap:
The most likely cause of the blend doors not working is an interruption of vacuum to the Mode Selector.
You can remove the HVAC panel to see if the vac hose is still connected, if the vac hose pull air while the engine is running, and if not trace it back to the pinch or break.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Spin Me This Week . . . I’ll Spin You Next Week
.
Joined: May 2004
Posts: 5,337
Likes: 71
From: Lexington, SC
Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: AC Anxiety
Trace the larger power wire to your fan harness over the box along underneath the cowl. You'll find a connector near the center of the windshield cowl where it plugs into the engine harness. This connector will crumble apart in your hands as you fiddle with it. Cut it out and replace it with a heavy guage connector or splice. Your high speed fan will now work.
Joined: Aug 1999
Posts: 19,282
Likes: 103
From: Lawrence, KS
Car: Met. Silver 85 IROC/Sold
Engine: 350 HO Deluxe (350ci/330hp)
Transmission: T-5 (Non-WC)
Axle/Gears: Limited Slip 3.23's
Re: AC positions and fan HI not working
Junior Member
Joined: Jan 2012
Posts: 90
Likes: 0
From: Arkansas
Car: 1985 Z28
Engine: 350
Re: AC Anxiety
Trace the larger power wire to your fan harness over the box along underneath the cowl. You'll find a connector near the center of the windshield cowl where it plugs into the engine harness. This connector will crumble apart in your hands as you fiddle with it. Cut it out and replace it with a heavy guage connector or splice. Your high speed fan will now work.
Thanks NAF
Jim J
Thread Starter
Member
iTrader: (1)
Joined: Sep 2011
Posts: 316
Likes: 0
From: Birmingham, Alabama!!!
Car: 1988 Iroc-Z
Engine: 350 TPI; Stock internals
Transmission: 700r4; TCI-CPVB; BW Hi-Frition
Axle/Gears: 4th gen 7.5 w/ 3:42 gear
Re: AC positions and fan HI not working
I'll have to check that out this weekend... Thanks for the info fellas
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