New AC compressor won’t cycle

[college man]

While the system is under vacuum you need to add as much_x000D_
system charge as you can before even trying to run the compressor._x000D_
The low pressure switch must see enough pressure to close to bring_x000D_
the compressor on.

Topic

[John B Kobberstad]

[quote]Quoted From diygeo: _x000D_
_x000D_
I ‘diagnosed’ my AC problem to be a faulty compressor. A gauge set was used to see if there was pressure in the system. There was. Next, I checked if the compressor was getting any voltage. It was, when AC was set to

[dreamer2355]

Was the A/C clutch already installed on the new compressor?_x000D_
_x000D_
Did you try to jumper the pressure switch to see if the compressor engages?

[diygeo]

Quoted From dreamer2355: _x000D_
_x000D_
Was the A/C clutch already installed on the new compressor?_x000D_
_x000D_
Did you try to jumper the pressure switch to see if the compressor engages?

_x000D_
_x000D_
I installed a clutch/compressor assembly._x000D_
I measured syste

[college man]

seeing 13.5 v at the compressor is kind of high but should be engaging.

[rice400]

check the air gap of the compressor clutch plate

[John B Kobberstad]

Quoted From college man:_x000D_
_x000D_
seeing 13.5 v at the compressor is kind of high but should be engaging.

_x000D_
_x000D_
Why would 13.5V be high if the engine is running? Where would the voltage drop be? It should have B+ at the compressor clutch coil

[dreamer2355]

You need to look at circuit design via a wiring diagram and see how the pressure switches work and are activated._x000D_
_x000D_
I would ‘assume’ the air gap is correct if the compressor came with a clutch installed for your specific application, thus why i asked tha

[John B Kobberstad]

I think it may be the 1 amp diode in the power line that plugs into the compressor clutch from the clutch relay that is bad. The diode may be allowing B+ to ground side of the compressor clutch. With no path to ground the clutch will not engage. Either th

[John B Kobberstad]

Tried to post schematic but I’ve got it in .pdf and can only post .jpg and .gif here sorry

[EricTheCarGuy]

Here is a video I did on charging an AC system that might provide some help._x000D_
http://www.youtube.com/watch?v=lglPJuBXVeE

[diygeo]

I rechecked the voltages to see if the diode was bad. To measure, I disconnected the connector from the compressor, then measured across the connector (Dark Green wire and Black wire)_x000D_
Voltage was ~0V for any AC switch setting, until engine was running. I

[college man]

With the car off. pull the connector. ohm out the coil on the compressor._x000D_
see if you have a resistance reading. you may have an open coil. if you_x000D_
can take the reading after the diode.

[EricTheCarGuy]

[quote]Quoted From johnbkobb: _x000D_
_x000D_
pressure switch (Hi or Low) if I’m not mistaken is electrical (at least on my vehicle they are). Pressure relief valve, which is a safety device also, is mechanical and not electrical and integrated into the compre

[EricTheCarGuy]

A pressure switch is a mechanical device that does not get hooked to any electrical connector.

[John B Kobberstad]

[quote]Quoted From EricTheCarGuy:_x000D_
_x000D_
A pressure switch is a mechanical device that does not get hooked to any electrical connector.

[Author]

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