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:huh: 2003 Toyota Sequoia. The A/c is not cold. The compressor is good, the charge seems good on the low side, however the condenser fan are not coming on. Its not activating at any time. Relays are good, fuses are good, and i jumped the high pressure switch to ground to force the fan on, and it worked. Is my high pressure side pressure too low to activate the switch? Could that switch be a failure? I am going to pick up a set of manifold gauges this weekend. I cant confidently say the low side charge is good being that i am using a cheap recharge kit gauge.
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As you have already acknowledged, you need to fit a proper set of gauges to find out what the low and high pressures actually are. The gauges that come on the recharge kits are not suitable. They are barely adequate to use to top up a charge. I have seen many that were way off (I have three of them in my garage that are anywhere from 5-10 psi off when compared with my professional gauges).
The high pressure switch will activate the fan when the high side exceeds ~250psi. The low pressure switch will not engage the compressor clutch if the low side pressure is below ~20 psi. If your charge is low, the head pressure will not exceed that and therefore the fan will not turn on, and if it is below 20psi the clutch will not engage. A properly functioning and charged R134a system should show pressures similar to the following: At 90°F, low=35-45psi, high=200-250psi.
Here is a chart that will indicate what some of the common causes of pressure faults are. This is not an exhaustive chart, there are situations that fall outside its scope. However, it can be a good starting point.
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