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P1633 Fault Code on 2001 Ford Taurus SEL 3.0L V6: Diagnosis and Solutions

Model: 2001 Ford Taurus SEL 3.0L V-6 Fault Code: P1633 Posted: 2006-09-28 20:50

I recently received a P1633 diagnostic code on my 2001 Ford Taurus SEL with approximately 99,000 miles. Before this code appeared, the A/C clutch was making severe rattling noises. Since the code came up, the rattling has stopped entirely, but the air conditioning system no longer functions. There is limited available information about P1633 specifically for Ford vehicles. Can anyone provide insight into what might be causing this issue or how to resolve it?

Related fault codes

P1633

Comments (3)

Anonymous 2006-09-29 17:18

The P1633 code indicates that the keep-alive power supply is below the required threshold. Potential causes include a weak battery, an underperforming alternator, faulty wiring, or a malfunctioning ECM. Is your alternator producing any unusual noise? Please check for signs of wear or vibration.

Anonymous 2006-09-30 19:59

I performed a load test on the battery, which passed; the alternator was also tested and found to be functioning properly. During alternator removal, I replaced the idler bearing as it was noisy—though I suspect that might have been the source of the earlier noise. After reassembly, the rattling has stopped, but the P1633 code persists. The A/C system remains inoperative. I believe the issue may now be originating from the air conditioning clutch itself, yet the diagnostic code still appears. Any additional troubleshooting suggestions would be greatly appreciated.

Anonymous 2006-10-01 21:00

Was the battery disconnected at any point before retrieving the fault codes? Ensure all battery terminals and connections are clean and free of corrosion. Try disconnecting the Powertrain Control Module (PCM) and use a digital multimeter to measure voltage at its connector—this should read at or above battery voltage. While monitoring, gently shake and bend the wiring harness to see if the reading drops below 10.5 volts. If you're located in Manteca, CA, I used to have family members living there who may be able to assist with local insights.