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AC shortcycling


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avin
New User

May 24, 2023, 5:20 AM

Post #1 of 6 (1021 views)
AC shortcycling Sign In

Hello there,

My car AC was shortcycling and then I charged it, before charging low side pressure was hunting and got stable at 30-35psi. After charge the pressure was about 40-45 psi.

However, now the compressor turns on initially for just a sec and then disengages and stays that way.

1. overcharging should have occurred at more than 60psi?
2. are pressure sensors faulty?


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

May 24, 2023, 6:12 AM

Post #2 of 6 (1019 views)
Re: AC shortcycling Sign In

First, don't ask a question here without posting the year, make, model, and engine size of your vehicle.

People will never learn just how dangerous those DIY charging kits are.

Low refrigerant is not the only cause of short cycling. There are dozens of possible causes and some will do a lot of damage. Overcharging is very dangerous and damaging.

You should NEVER top off a system relying on pressures, especially when you don't even have a high pressure reading. You should never top it off at all.

The system requires a very specific amount of refrigerant to operate correctly and the ONLY way to measure that is by completely evacuating the system and charging with the exact WEIGHED amount of refrigerant. Only then can you look at the high/low pressure readings and come to any conclusion.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



(This post was edited by Hammer Time on May 24, 2023, 6:13 AM)


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

May 24, 2023, 7:08 AM

Post #3 of 6 (1008 views)
Re: AC shortcycling Sign In

That type of info is all over stuff sold isn't worth crap. As HT said, start from zero, measure in right amount into a well held vacuum. If not that much just wasted time and products.

Always first is WHAT IS THIS THING?
Include why you replaced a compressor as well,
Tom



Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

May 24, 2023, 7:10 AM

Post #4 of 6 (1004 views)
Re: AC shortcycling Sign In


Quote
Include why you replaced a compressor as well,
Tom


Where did it say that?



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

May 24, 2023, 8:36 AM

Post #5 of 6 (993 views)
Re: AC shortcycling Sign In

It didn't, misread 'now' for 'new' doesn't matter for now, T


Sidom
Veteran / Moderator
Sidom profile image

May 24, 2023, 9:44 AM

Post #6 of 6 (986 views)
Re: AC shortcycling Sign In

To properly diag the a/c system you will need a manifold gauge set, a recycler would be good and depending on the year of the car, you may need a scan tool.
Those DIY kits are designed for cars with small leaks. You put the can in and fix the problem (temporarily).
If it doesn't fix the problem then you need to take it to a shop.






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