Q: I have a 2003 Buick Rendezvous. After the dealer did a brake job, the red "Brake" warning light on the dash came on, along with an audible alarm. The dealer said they didn't cause it, don't know why it's doing it and don't know how to fix it. They said I could disconnect the wire to the radio speaker but they would not do this for me.

A: Really? Even without hearing both sides of the story, it's hard for me to believe an authorized dealer would suggest a car owner ignore a brake warning light and audible warning signal. Beyond this, how a dealer could tell you they don't know what or why the warning light is on without checking the car is just as questionable.

Typically, there are three reasons the red "Brake" warning light comes on" low brake fluid level in the reservoir, the parking brake still engaged or a problem with the hydraulic brake system.

The dealer should have checked fluid level in the brake master cylinder reservoir, checked that mechanical components of the parking brake or its electrical switch are not sticking and, most important, scanned for any brake system, ABS or TCS (traction control system) fault codes.

For the dealer to have serviced the brake system, then deny causing the brake warning light to illuminate without any investigation and to suggest that you ignore the light and disable the audible warning is, frankly, almost unbelievable.

Q: My daughter has a 2004 Saturn Ion that has a problem starting when overnight temperatures drop to zero or below. She turns the key and it just goes "Click, click, click," or starts to turn over, then stops. She leaves it sit for 15-20 minutes and then it starts right away. During warm weather it starts fine. Can you help?

A: Check the battery terminals, connections and cables. The "Click, click, click" is typically a sign that the battery is weak or connections are so poor that not enough amperage reaches the starter motor to crank over the engine. The electrical resistance through poor connections during several starting attempts may actually warm up the connections and battery enough to enable an engine start.

Load-test the battery itself. An aged battery operating in subzero temperatures may well be the culprit.

Q: My granddaughter has a 2008 Chevy Uplander with 65,500 miles. In early January during a nice spell of weather that exposed some of our famous potholes, I hit one. Shortly after that the "Service ABS System," "Service Traction System" and "Service Stability System" warning lights came on in a blinking rotation. Because the weather has been so bad recently, I'm hoping to get some advice on what to look for before crawling under the car. The brakes work fine and I'm still driving the car.

A: Have a shop plug in a scan tool and identify the specific C-series DTC fault codes relating to this issue. The most likely cause is a damaged wheel speed sensor or harness. The information gathered by these sensors and fed to the electronic brake control module determines if ABS or TCS function is appropriate. If the signal from one or more wheel-speed sensors is absent or inaccurate, a fault code is generated, the systems are disabled and warning lights illuminate.

You probably won't have to crawl under the car. The scan tool should identify which wheel speed sensors are at fault. You can access the sensors and their harnesses by removing the specific wheel in question.