73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Interior & Equipment => Heating, Ventilation & Air Conditioning (HVAC) => Topic started by: fiddler on June 22, 2014, 04:58:50 pm
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Anybody removed an A/C control cluster from a 1974 stepside C10? It appears that my A/C compressor switch is not making contact as I get no 12 volts to the compressor when the A/C is on. Looking to learn from somebody elses experience before I end up with the truck engine removed or down to the frame to get the switch out because I did not twist the cluster just so or some such. Any help would be appreciated. Thanks much.
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Comes out pretty easy
Think you gotta pull the plastic bezel first. Them 4!screws holding control in
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Check and make sure you are getting power TO the switch before you pull it out
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Thanks for the inputs. I have the bezel off. I have the screws off. I have dropped the radio down for clearance. I have turned the AC cluster every which way but loose but I still cant get it out. I was hoping to get it out in the cab so I could measure voltages and continuity and such. The good news is that I ran the truck with air set to full on and then spliced 12 VDC into the AC clutch wire and the system pulls down and blows cold! I am pretty sure the switch is the culprit. So I will keep trying. Maybe I can pull the harnesses while the switch is still under the dash and that would give me the clearance I need.
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Thanks for the inputs. I have the bezel off. I have the screws off. I have dropped the radio down for clearance. I have turned the AC cluster every which way but loose but I still cant get it out. I was hoping to get it out in the cab so I could measure voltages and continuity and such. The good news is that I ran the truck with air set to full on and then spliced 12 VDC into the AC clutch wire and the system pulls down and blows cold! I am pretty sure the switch is the culprit. So I will keep trying. Maybe I can pull the harnesses while the switch is still under the dash and that would give me the clearance I need.
Check for some
Clips or anchors on the cable
That runs to the flaps under the glove box
You may have to unhook that cable to be able to twist the control
Enough to get it out
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Thanks much. I'll try that tomorrow.
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OK roundhouse, that isn't helping. Maybe I misunderstood about the plastic bezel. You were talking about the main one that covers the speedometer and gauges right? Or maybe I need to take the plastic bezel off of the switch cluster to find 4 screws underneath it and pull the front off of the switch cluster?? If this wasn't a hobby I would be plenty frustrated right now. As it is...just amused at how they did this!!
Thanks in advance for any more advice you have.
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OK so I have the main bezel off and the screws removed from the AC control cluster and it it free to move about but I can't seem to twist it just so to get it out of the dash. I can get the top right and bottom center screw tabs out but I can't get a 3rd tab out no matter how turn the thing. I need to test the AC switch as my AC clutch does not energize. I bypassed the switch and got the air to blow cold but I need to verify switch before ordering a new control cluster.
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Did you check with the manual in the tech section found HERE (http://forum.73-87chevytrucks.com/smforum/index.php?topic=25639.msg213706#msg213706).
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Thanks! It was in the manual. On the 74 it needs to be disassembled and drop out the bottom. I remember I was going to look there but had problems with logging in, and by the time I reset password and all I forgot who I was....let alone what I was doing. I now have the manual on my computer. 978 pages of gold!
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Why are you taking it out? Sounds like you are backward troubleshooting your problem.
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So no power to the compressor clutch. I was trying to get the harnesses out to where I can ohm paths. I got it out and finally found (here) the right wiring diagram. Turns out somewhere along the line the wiring was moved around a bit. Some disconnected, some reconnected in wrong spots. Anyway, straightened out wiring and added a line to after market fan controller so radiator fan comes on whenever air conditioning is on, only to discover that the air conditioner is always on. (Looks to be by design). Need to move my wire to where the radiator fan comes on when the clutch is energized. That way I won't be running the fan all of the time.
Thanks for the reply!
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Thanks everybody! So I got the air working perfectly as it was originally designed to work. With the new interior that was installed before I bought the truck it is starting to look pretty good in there. Coming along a bit at a time. Next step is to repair the turn signal indicator so it cancels and to get the horn button wired up. Right now the horn is on a toggle switch at the bottom of the dash board. Just trying to get back to stock everything. (May take some doing for the tail lights as they are from an International Harvester Pickup truck).
Thanks again...
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So what was your problem with the AC?