Questioni have a 91 silverodo and the ac will work fine if u unhook the battery and reset it for about 5 to 8 miles the it stops and ac flashes on the climate contrl box i changed the climate control box with a used one and it done the same thing
AnswerBrian,
The dash HVAC programmer (or climate control head) in a Silverado has the ability to shut the compressor down should it see a logic problem. The fact that the light is blinking when it sees a problem generally means the HVAC head is working and doing its job. You will find the problem when you find out what the programmer 'thinks' is the problem.
As with all Automotive AC systems the first place to start is to make sure the system is properly charged. Overcharged and undercharged system can cause a myriad of symptoms that in most cases encourage people to replace the wrong parts.
A C1500 programmer watches the low pressure cycling switch (the sensor on the accumulator) to determine when to engage the compressor clutch. Should the system pressure be too low (excessive cycling of compressor) for a determined amount of time it will go into protection mode and shut the compressor down. It is unlikely you have a method of removing/measuring and charging the system so I can only offer a few tidbits of info here as I really feel this system might be low on refrigerant.
It is either A: Low on refrigerant B: a defective low side cycling switch or C: plugged orifice tube in the liquid line.
I can't stress enough that it is probably low on refrigerant. Identify what is in the system before you top it up. Feel free to ask more questions.
Wayne
Revision:
I looked the specification up for low refrigerant operation. If the AC clutch stays on for less than 1.5 second, for 10 consecutive cycles, an AC fault is indicated and the AC light is illuminated in a flashing sequence and clutch actuation is cancelled until programmer is reset. This is to protect compressor from self destruction from oil starvation.
Wayne
