95 Towncar Speed Control

[bob2231]

My Dad just bought a 95 Town Car. On the way home he found that the cruise control doesn't engage. I pulled the fuse and it's fine. Any suggestions what to check next ?
Thanks

[Towncar]

Are there any other symptoms? --

The speed control system consists of:

• speed control servo
• speed control cable
• vehicle speed sensor (VSS)
• horn relay and bracket
• speed control actuator switch
• stoplight switch (BOO)
• brake pressure control valve with integral deactivator switch
• air bag sliding contact

[bob2231]

[quote=Towncar]Are there any other symptoms? --

Not that I know of. It's generally in nice shape and the old owner said he didn't know the cruise wasn't working. We looked at the manual, and followed the insrtuctions but whae you let off the gas it just starts coasting down.
Thanks for responding.
Bob

[Towncar]

Check a few things before we dive fully into this:
1) Do the brake lights work?
2) Is the cable intact from the servo to the throttle cable?
2) Does the "Speed Control" indicator light up on the dash when you activate the system?

I may be able to print the entire diagnosis text from my 96 manual to PDF's if this becomes elusive.

BTW, What model is your Town Car?

[bob2231]

I can't check the cable until later, but I know the brake lights and signals work. And I didn't see any dash light when we tried it.
Thanks

[bob2231]

Sorry, forgot. It's a 95 Cartier.

[Towncar]

Originally Posted by bob2231

I can't check the cable until later, but I know the brake lights and signals work. And I didn't see any dash light when we tried it.
Thanks

OK, there's a bit of a trick to activating the system, it dosn't come on immediately after pressing the ON button.

My terminology, "Come on" means the "Speed Control" text is displayed between the Odometer and the Speedometer. You can't miss that one

The system won't activate under 25MPH. Over 25MPH:
Press the ON button once, (nothing appears to happen)
Press the Set Accel button once, the "Speed Control" text confirms activation.
(See attached screenshot, click to enlarge).


If that sequence didn't work, we'll have to begin a diagnostic routine.

1st step in "Speed Control won't come on" is:
Verify proper horn operation.
Verify stoplamp operation.
Check circuit fuses.
Town Car - 3 fuses
Power Distribution Box fuse "L" (20A), Fuse Junction Panel fuse 7 (15A) and 16 (15A).

[bob2231]

Thanks, I'll check the fuses when he gats back. I know the horn and brake lights were working ok.

[bob2231]

Ok, an update. I noticed this evening that the 3rd brake light was working, but that the tail\brake lights weren't on. That was as he was leaving. When he got back I told him what I had learned here. He says the horn is working, but now the signals and emergency flashers aren't. I had noticed that a flasher unit is missing from the panel under the dash.
I guess earlier today he stopped by the mechanic he goes to and after a fairly quick check, was told that all the under hood stuff seems to be ok, including the fuse and cable.
I guess at this point with the signal complication I'll check all the bulbs, under dash fuses, and put in a flasher. There seems to be a problem with the passenger compartment elec. system and that's scary.
I'll post what I find.

[Towncar]

Hey Bob...
The BOO (brake on/off) switch could be causing all these problems. It's interlinked to a few different systems, and if it's not functioning 100% you can get quite a few strange symptoms.

It's not common to have a bad BOO switch, but it does happen with the Town Cars.

In case you're wondering the price, I searched this one online:
Description-----------------------Year-----MSRP Price---Your Price
STOPLAMP SWITCH, Town Car-----92-03---$17.11-------$10.40

[bob2231]

Thanks for the suggestion. I'll have him look at the bulbs and fuses and if they all look ok I can pick up a switch on the way home from work. We'll see how it goes.

[bob2231]

I was finally able to put in a new switch but it made no difference. Everything seems to work fine except the cruise control. Unfortunately now I think he's going to take it to the dealer.

[bob2231]

We got the answer I didn't want from the dealer. The wiring ring in the steering wheel is going bad. $350 installed, but that should fix it.

[Towncar]

Originally Posted by bob2231

We got the answer I didn't want from the dealer. The wiring ring in the steering wheel is going bad. $350 installed, but that should fix it.

Damn, I hate when that happens !!!

[CNYSlider]

Hi Towncar! The names Pete. Have a 96 TC Sig that the cruise control doesn't work. Found you post and wondering if you can help? Everything seems to work, as in you questions, but it doesn't. Light on dash comes on, but no cruise :<( The cable is connected and I'm asssuming the servo is the little box mounted up by the driver's side hood hinge? Where the cable goesinto the servo,clips off easily and you find the cable wrapped around a small white pully. All looks good, soasssumed the servo died or is burnt out. After reading this, figured I asked if there's other thing to check out before buying one. Have no idea how much it would cost to begin with and sounds like it could be something simple. Any idea on the approximate cost of one if it is that? Would appreciate any help you could povide to pin it down. Thanks! Take it Easy, Pete