Chrysler Imperial A/C Compressor Cut-Off Switch Guide: 1981-1993
If your classic Imperial's A/C isn't blowing cold, a small, inexpensive switch could be the culprit.
- Verify your Imperial's generation (1981-83 vs. 1990-93) to ensure you order the correct part.
- Confirm the switch is actually faulty with a pressure test; low refrigerant causes identical symptoms.
- Aftermarket brands like Four Seasons are the only practical option, offering a cost-effective but potentially less durable fix.
- Replacing the switch is a simple DIY job if it has a Schrader valve, but requires professional service if it does not.
Understanding Your Imperial's A/C System
Important Note for Owners: The 1981-1993 Chrysler Imperial was built in two distinct generations: 1981-1983 and 1990-1993. A/C system components, including pressure switches, are often different between these two versions. Always verify the exact part required for your specific model year before purchasing.
When your Imperial's air conditioning stops working, it's easy to assume a major, expensive component has failed. However, the problem can often be a small, simple part like the A/C compressor cut-off switch. This switch acts as a guardian for your A/C compressor, and when it fails, it can mimic more serious issues.
Common Symptoms of a Bad A/C Cut-Off Switch
A failing cut-off switch can cause several noticeable problems. Here are the most common signs to watch for:
- Intermittent Cooling: The A/C works for a few minutes and then suddenly stops, only to start working again later. This happens when a faulty switch sends erratic signals, randomly shutting down the compressor.
- A/C Blows Warm Air: The most obvious symptom is a complete lack of cold air. A bad switch can fail to send the signal to engage the compressor, so the cooling cycle never begins.
- Compressor Clutch Doesn't Engage: When you turn on the A/C, you should hear a 'click' as the compressor clutch engages. If you don't hear this and the A/C isn't working, the cut-off switch could be preventing the clutch from receiving power.
- Rapid Clicking Noises: You might hear fast, repeated clicking from the engine bay. This is the sound of the compressor clutch trying to engage and disengage rapidly due to faulty pressure readings from the switch.
Pro Tip: Many of these symptoms, especially a non-working A/C, can also be caused by low refrigerant. The switch is designed to shut off the system in this case. Before replacing the switch, it's wise to have a professional check the system's refrigerant pressure to confirm the actual cause of the problem.
Choosing the Right Aftermarket Switch
For a vehicle of this age, finding new original equipment (OEM) parts is nearly impossible. The market for the 1981-1993 Imperial consists entirely of aftermarket solutions.
- OEM Quality: New OEM switches for this vehicle are no longer produced by Chrysler. Any that might be found would be "New Old Stock" (NOS) and likely very expensive and difficult to locate.
- Aftermarket Quality (Four Seasons, Global Parts): Brands like Four Seasons and Global Parts provide affordable and widely available replacements. Four Seasons is a well-known aftermarket A/C parts supplier. While some users find their parts to be a reliable alternative to OEM, others have noted inconsistent quality. These brands represent a standard, budget-friendly tier. They will get your A/C running again, but may not have the same durability or precise calibration as the original part.
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket | $9.01 - $15.44 |
| New OEM | Generally Not Available |
| Shop Labor | $100 - $250 |
Frequently Asked Questions (FAQ)
Can I replace the A/C cut-off switch myself?
Yes, this is often a simple repair. The switch is typically screwed into one of the A/C lines or the receiver/drier. Many are fitted with a Schrader valve, which means you can unscrew the old switch and install the new one without losing refrigerant. If there is no Schrader valve, the system must be professionally evacuated before replacement and recharged after. The difficulty is low, but confirm access and the valve type first.
Is a bad switch the same as a refrigerant leak?
No. A low refrigerant level will cause the low-pressure cut-off switch to do its job and shut down the compressor to prevent damage. A bad switch, however, may shut the system down even when refrigerant levels are perfectly fine. A proper diagnosis using A/C manifold gauges is the only way to tell the difference.
Are there any recalls for the Imperial's A/C system?
No recalls related to the A/C system, compressor, or cut-off switch have been issued by the NHTSA for the 1981-1983 or 1990-1993 Chrysler Imperial.
Why is it important to fix this?
Besides the obvious comfort of having working A/C, a faulty switch can cause the compressor to cycle rapidly, leading to premature wear on the compressor clutch. If the switch fails in a way that it *doesn't* shut off the system during a real pressure problem, it could lead to the destruction of your A/C compressor.
Technical Specifications
Functions as a high and/or low-side pressure safety switch to protect the A/C compressor.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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