! More Crown Vic help, this time electrical!

Topic: ! More Crown Vic help, this time electrical! (Read 2544 times) previous topic - next topic

! More Crown Vic help, this time electrical!

Reply #15 – January 23, 2008, 06:41:01 PM

On second thought, maybe fuse 22 circuit is also causing the horn problem.

The horn, fuse 5 in the battery junction box, horn relay also in the battery junction box.
The horn relay gets its' ground through the horn switches and the "sliding air bag contacts" then through the speed control servo controller.
If the speed control servo controller is missing its' hot at all times voltage from fuse 22 will it interupt the ground for the horn?

! More Crown Vic help, this time electrical!

Reply #16 – January 23, 2008, 08:47:44 PM

Thanks guys!

I checked out the pedal stop switch really close and found 2 wires spliced in going back towards the firewall. Sure enough they were just cut on the other end and touching the frame, causing fuse #22 to blow. I clipped the wires out and threw some electrical tape on the nubs. New fuse and drove all day with no problems (brake lights work perfect, shift interlock functions correctly, hazards work).

So that problem is solved but I do still have a few. The cruise worked for awhile this morning, but now it doesn't. The horn is also inop. I replaced the fuses under-dash for both, but no dice. Could it be the underhood fuses or relays? Or should I keep digging around in the footwell?

BTW, I bought a new lifetime stoplight switch anyways, it was $7. I'll throw it in if it's starts acting up again, until then it can hang out in the glovebox.

! More Crown Vic help, this time electrical!

Reply #17 – January 23, 2008, 09:53:17 PM

The fuse and the relay for the horn are in the Battery Junction Box (under the hood).
It is fuse #5 and relay #2.

Fuse #5 is also the turn-on voltage for the cruise. If fuse #5 is blown or relay #2 unplugged you will not be able to turn-on the cruise or blow the horn.

There is a dark blue wire from the horn relay to the steering column.

The ground for the relay is through the horn switch on the steering wheel. This is the same ground used by the cruise switches on the steering wheel.
The ground is a Dark Green/Orange wire from the steering column to the cruise control servo under the hood.

They don't use a vacuum servo motor like our foxes. It is an electric stepper motor. The control module is not seperate, it is built into the servo assembly.

! More Crown Vic help, this time electrical!

Reply #18 – January 23, 2008, 09:56:36 PM

Wow! Thanks for the info! I'll check that underhood stuff out tomorrow since it's the cruise and horn that are both inop.

! More Crown Vic help, this time electrical!

Reply #19 – January 23, 2008, 10:31:24 PM

Did the horn ever work since you bought it? Another feature of most sirens is the "horn ring" circuit. It gives the "squelch burst" sound I described earlier, but it is activated by tapping into the horn switch so the cop can clear intersections. The horn wire is cut and the siren box is put in between the cut (electrically, not physically) so that when the siren is off the horn functions normally, but when it's on the squelch burst/air horn sound is made. Often when stripping the cars the stripper isn't worried about making the car work right, he's worried about getting the police equipment out.

! More Crown Vic help, this time electrical!

Reply #20 – January 24, 2008, 12:17:55 AM

You know Carm, I don't think I ever checked the horn. Where is that cut usually made?

! More Crown Vic help, this time electrical!

Reply #21 – January 24, 2008, 08:30:12 AM

Usually near the base of the column. Our shop stopped doing it years ago, before I started working there so I don't really remember exactly where it was. I only know about it because I had to strip some of the cars that had it done when I first started working there, and was instructed to simply cut the wires coming out of the siren box (we are paid a flat rate to strip 'em, and that flat rate isn't much so we're not exactly meticulous).

! More Crown Vic help, this time electrical!

Reply #22 – January 24, 2008, 04:04:05 PM

It just occurred to me that you mentioned your airbag light is on as well. Have you ever had the steering wheel off? If so it's likely that you rotated the "clock spring" coil behind the steering wheel. When removing the steering wheel it's extremely important to make absolutely sure that the clock spring does not rotate from its original position. If you rotate it and reinstall the wheel it'll pull itself apart the first time you rotate the wheel to full lock (if you've rotated it a bunch of times full lock isn't even necessary).

Unfortunately, if you've pulled it apart, it's fvcked. You need a new one.

The horn, cruise, and airbag all get their connections through the clockspring. Since you've got problems with all three I'd bet this is your problem.

! More Crown Vic help, this time electrical!

Reply #23 – January 24, 2008, 04:31:45 PM

No airbag light anymore. It was 100% the driver's seat harness.

I have no cruise (which did work), and no horn as my only problems.

Steering wheel has never been apart (by me anyways, though the department records don't show anything either).