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How do I Bypass ac compressor relay

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Old 05-19-2019, 05:15 PM
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Default How do I Bypass ac compressor relay

So my ac clutch won't engage. I believe it is because I purged the system when changing the condenser and now it is too low.

Can't I bypass the relay and give it direct power? I'd like to do so using a wire and the relay connectors, but I am unsure where to run the wire. I'd like to do it like in this video here -

Anyone know how I can do this? Where do I place the paperclip wires?

I was also thinking of going directly from the battery to the compressor, but there are so many tubes for the rear ac running over my compressor that I have a hard time accessing the wiring.

Thanks in advance.
 
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Old 05-19-2019, 06:33 PM
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if you run the compressor with low charge...you will kill it. that is the point of a low pressure switch...to protect the compressor and to stop evaporator freezing.
 
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Old 05-19-2019, 06:48 PM
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Ok, so what can I do? Can the evap freeze with no refrigerant in the system? How else can I fill the system?
Thanks
 
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Old 05-20-2019, 07:10 AM
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If you have one of the 'top off' cans that you can get at walmart, just hook it up, and shoot some into the system. If the system is completely empty, it will likely take a couple cans before the system is full. (it will start cycling when you hit minimum pressure for the low pressure switch, but, it won't stay on for long, until you get closer to full.)

Is there any oil in the system?
 
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Old 05-20-2019, 08:37 AM
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I do have one of those cans. I've been trying to run it, but it doesn't seem the system is pulling in any of it. There is only minimal oil in the system. I am trying to add some as well while adding the top off can.

On a side note, my valve for the can may be bad so I am going to address that today before I do anything else.

So if the issue isn't my valve, how can I get fluid into the system to reach the minimum for the low pressure switch?

Is that relay bypass totally out of the question?
 
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Old 05-20-2019, 02:28 PM
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Bypassing the relay with the system completely empty is a bad plan. You can smoke the compressor real easy doing that, and it makes the repair hideously expensive, as all the junk from the compressor gets circulated throughout the system..... You don't wanna go there.

If the system isn't taking anything from the can, address that problem first. You should be able to bring the pressure up far enough that the compressor will start cycling, without having to jumper/bypass anything.
 
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Old 05-20-2019, 04:02 PM
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Thanks, I actually got lucky. The compressor turned on. I ran the vehicle to get a new valve for the top off can and then left it idling while I was setting up the top off can on the new valve. When I checked the compressor wasn't on, but after like 15 minutes it came on and I was able to get fluid in there.

I guess my next issue is why isn't the compressor turning on sooner, but I'll start another thread on that.

Thanks again.
 
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Old 05-20-2019, 05:29 PM
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Probably pressure is still low.
 


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