Hello,
My A/C unit keeps turning on and off. When we turn on the A/C it will run for a min. or two and then kick off and then come back on. It keeps doing it over and over. I replaced the thermostat and the wire going to the outside unit. Is it a low voltage problem?

Does the fan inside also go on and off or just the outdoor unit?

Hello Josh,
The fan inside stays on. It's the unit outside that will run for about a min. or two and then shuts down clicks two or three times and starts to run again. I have replaced the contactor outside also.

Ok so it is just a outdoor problem, next question is the fan and compressor both kicking in and out? Or is it one or the other? Sounds like it may be a low pressure switch. Freon pressure is higher while the unit is not running, when it kicks on the pressure will drop causing the switch to kick out. After it kicks out the pressure will again rise causing the unit to come back on. Then off and so forth

Hay Josh,

The contact clicks on and off. I had a metter on it while it was going on and off and it was still reading 24 to 25 volts.

It is a Carrier 3 ton unit

If it still has the 24 volts then I am about 95% sure it is a low pressure switch problem.

Where is the low pressure switch? What dose it look like?

Dose it have wires connected to it or is it welded to the freon line?

Quote:

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Originally Posted by emaxxdr

Dose it have wires conected to it or is it welded to the freon line?

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Both, it is inside the ac unit, may have 2 of them one on little line for high pressure, one on big line for low pressure. Odds are you are probably low on freon, the odds of having a bad switch are not very good. But I have seen bad switchs before.