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Town Car owner unable to get cruise under control

  • Article by: PAUL BRAND
  • Star Tribune
  • March 6, 2011 - 4:01 PM

QI have a 1990 Lincoln Town Car with a 302-cubic-inch V8 engine. The car is in near-showroom condition and well-maintained. When I hit the brake to disengage the cruise control, 50 to 70 percent of the time it reengages when I take my foot off the brake pedal. If I brake until I'm under 35 mph, I know it can't reengage. Often, I don't want to brake that much, especially if cars are behind me, so I've gotten in the habit of hitting the "off" button on the steering wheel each time it happens. Any ideas?

AGood habit. Just like preparing for the potential of a stuck throttle by practicing the quick movement of shifting into neutral or turning off the key, knowing instinctively what to do in an emergency situation can be a huge factor in avoiding a serious incident.

Now to your Town Car. My Alldata automotive database outlines the adjustment procedure for the cruise control vacuum "dump" valve and the ABS pedal position sensor switch, both mounted on the brake pedal linkage under the dash. Both must be set correctly to make sure that the cruise control completely disengages when you depress the brake pedal. Check for the correct .030-inch gap between the dump valve and pedal pad. To readjust the ABS switch, disconnect the switch hook, push it fully back into the switch body, depress the brake pedal an inch or two to allow you to reconnect the hook, pull the brake pedal all the way back to its at-rest position, then push the switch body until all the slack is removed. Also, make sure the brake lights are working properly and that the brake light switch on the pedal is properly adjusted.

The most likely cause for the cruise control failing to completely disengage is one of these switches on the brake pedal mechanism failing to disconnect, or "dump," when you push the brake pedal.

QI drive a 2003 Mazda Protege with a 2.0-liter engine. The engine has an intermittent, high-pitched squeal that is either a belt or bearing squeal. The noise usually starts if it's damp outside or if I start the heater fan or air conditioning. If I get the rpms up to 3,000, the noise goes away and I feel a sudden surge of power in the engine. If the rpm drops, the noise returns. Can you help?

AThe noise probably is coming from one of the engine's drive belts. With the engine running and the squeal occurring, spray the underside of each drive belt in turn with aerosol brake clean, taking care to keep fingers and clothes clear of moving parts. If the noise stops momentarily when you spray one of the belts, the belt may need adjusting or replacing, or a bearing in the alternator or air-conditioning compressor is failing, causing excess drag.

QI have a 1998 Chevy K1500 with a six-cylinder engine and five-speed manual transmission. Five times this winter after plowing snow and letting the truck sit for a couple of days, when I try to start the truck it acts as if the battery is shorted out when turning the key. All the lights and accessories work until key is turned. If I rock the truck in gear, it will finally start. Bad spot on the starter?

APossibly, but a bad commutator segment on the starter would prevent the engine from cranking but wouldn't have the characteristic of a dead short. When you turned the key to "start," you'd likely get a click but nothing else. The problem sounds like a poor electrical connection or ground in the primary starting circuit or perhaps a bad starter solenoid or relay. Rocking the truck in gear may jiggle/wiggle/move things enough to create an adequate connection.

You plow snow with the truck, so moisture getting into the starter, starter drive gear or flywheel and then freezing may be a factor. Rocking the truck in gear may be breaking up this ice, allowing the starter to engage and crank the engine.

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