A/C System Help!!!

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78C10BigTen

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I took a video of the AC Compressor with A/C going Belt flopping around
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Cant you tighten the belt??? Just like a loose alt. belt it doesnt put out enough... at least thats kinda what im thinkin
 

jfkelley

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Cant you tighten the belt??? Just like a loose alt. belt it doesnt put out enough... at least thats kinda what im thinkin

Here is my A/C belt wobbling when the AC is turned on ..Is the Clutch going out ?

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78C10BigTen

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Watching the clutch it looks pretty straight when its running. Id still think that belt is not tight enough.
 

Arkansas_V8

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have an 1976 K10 Scottsdale 4X4, The A/C has been retrofitted it blows Semi Cold when Idling , But if I give it gas while sitting still the blower speeds up and blows cold, Also when you drive it you can hear it start blowing harder and its gets cold..A/C has been charged , All Ducts been inspected and are good..Do I need a new Clutch fan or Blower Motor ? Maybe one out of an 1994 Truck?..Plus the A/C Blows Max regardless what setting you have it on...Its HOT in Oklahoma Everyday way over in the 100’s today...Any Help or Advice would help ...Thanks !

I feel your pain man. Breathing the air is like a sauna. Humidity here is over 90%, with about the same temps. I am your border neighbor.

Sorry I am no help with the A/C, I always trash it.
 

1987 GMC Jimmy

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Something’s not right with the fan not blowing at the set speed. I would make sure nothing’s fried at the selector switch and that wiring isn’t hinky where the connector plugs into the resistor. You can follow it around some and see if something’s weird, which is what I’d do if you can’t find it right off the bat. If something shorted out or was bypassed, that could be part of it. I think the second part is related to your alternator/engine speed. The difference in voltage seems a bit much, and if your blower is say wired to the alternator output that would explain some things. That mini serp belt should be tight, no squeaking. I think some twang in the compressor belt with the clutch engaged is fine as long as it’s not slipping. As far as getting colder when the engine speeds up, I think that’s just par for the course in the A/C world. A different orifice tube, assuming yours isn’t plugged up, might perform better just sitting there, but you could potentially sacrifice highway performance. You could check your condensor surface temps all over with a heat gun to make sure nothing’s fishy. Hell, if the thing was just converted over since you’ve had it, and you’re not the one who did it, you can bet the system wasn’t flushed, the o-tube and accumulator weren’t replaced, and the system has plenty of mineral oil in it, which it shouldn’t have. There’s a lot that goes into quality A/C work, and many things can impact system performance.
 

eaglewingflight

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Some good posts here. I'll give a suggestion or 2. As far as your low performance of your AC at idle, I have a question: When you say retrofitted, this is new AC gauge ports for low and high side? Or was there more retrofitting done to the AC system? Who charged the system? Were actual AC gauges used? Its important to know what pressures are on the low side and high side of this system. Over charging the system may not cool at idle, however, you will hear/see AC compressor squeal at times due to the higher pressure. If system is undercharged, you will have poor performance with this system such as poor cooling or higher temps from your interior AC duct system.

I have a 1978 GMC 4x4, My dash volt meter looks the same as the pictures you provided. Use a good volt ohm meter to compare what battery voltage you see on this meter vrs your dash gauge at idle and high RPM. You may have an old tired dash volt meter. GM installed a high idle plunger to increase engine RPM at idle (approx 200 RPM higher than your normal idle RPM). Your K10 and my 78 k1500 doesn't have this high idle plunger. So, AC performance and engine idle performance suffers a bit.

Are you running a factory radiator fan? Is it a clutch fan? How old is this clutch fan? Is your radiator shroud installed?

As far as your electrical system is concerned, a previous post asked about your grounds. I agree with this. But check both battery to engine block ground AND engine block to frame ground AND block and or frame to firewall grounds. The more grounds the better! Another question is, what accessories in addition to the factory accessories are you running? Is your alternator capable of handling the load for all the electrical loads your running. Here is a general electrical system link that may or may not be helpful for you:

http://www.superchevy.com/how-to/additional-tech/1702-amperage-tips-when-wiring-your-chevy

As far as your blower motor blowing on high speed all the time, was there any rewiring done in this area? Here is a previous square body blower motor wiring post that may or may not help you:

https://www.gmsquarebody.com/threads/hvac-speed-control.24517/#post-464384

I hope any of this info helps!

I welcome any criticism and or good or bad comments from anyone. This guy needs help!
 

roundhouse

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Put a meter on the battery and check the voltage at idle with the ac on

Also check the voltage at the blower motor

And then check it with someone speeding the engine up

And check it with the ac turned off
 

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