2004 Crown Vic headlights and AC sporadic

I have a 2004 Crown Vic from the Highway Patrol. The headlights work most of the time. Recently the headlights cut off while I was driving, but they would work when I kept them on high beam. Other times they work just fine. Sometimes the AC is slow to cool (it blows just fine, but isn’t cooling). It takes perhaps 5 minutes till the air begins to cool.

Is there any connection between these two sporadic things? I care more about the headlights—what should I change? The headlight switch is $100 (for the non-police edition) and $180 for the police edition). If I need to change the switch, can I use the cheaper one? Should I try for a used switch. FYI—I also have a 1997 Police Crown Vic too, and that headlight switch broke a few years ago. It had totally dfferent symptoms though; it stayed on all the time, so I simply pulled the switch unit out of the dash and connected and disconnected the modular plug in order to control the lights. (Later, when I feared that I might “worry” the wires to the breaking point, I paid the money for a switch.)

I suggest that with two Crown Victorias you join www.crownvic.net. There are lots of people with retired police cars there. Unfortunately, the police cars often have abused wiring harnesses and that is most likely the cause of your problem with the headlights. The headlight problem could also be with the LCM (lighting control module). Sometime around 2004 the headlight relay in that module was a weak link. The relays tend to fail. The module is expensive, maybe $400. You can replace the relay if you are handy with circuit boards. To prevent failure I advise using an external relay hooked into the headlight wiring. This will benefit all aero Vics by increasing headlight brightness.

You need to do a diagnosis on the AC, pressures, compressor on time, compressor off time, compressor cycling,…

Check out crownvic.net. You won’t be sorry.