AUTO Q AND A: Why turn signals flash faster
Q: Recently I've noticed my turns signals flash considerably faster to the left side than the right. A friend said it may be caused by a burned out bulb, but all my lights seem to be working. What could cause this to happen?...
Q: Recently I've noticed my turns signals flash considerably faster to the left side than the right. A friend said it may be caused by a burned out bulb, but all my lights seem to be working. What could cause this to happen?
A: This should be an easy one. Your car's turn signal flasher unit is sensitive to the quantity of electrical current passing through it. With all the bulbs functioning properly it flashes at the normal rate, and should a bulb burn out or otherwise use less current, the flasher responds by changing its cycling rate. On older vehicles using a more primitive thermal flasher, reduced current causes a slower rate, and the electronic flasher used in newer vehicles does the opposite.
Since your flasher works properly for the right side, we'll assume it's not the problem. Let's start by verifying the function and brightness of all the exterior flashing lights. Try turning on the hazard flashers and carefully compare each side, front then rear. Some vehicles may use double bulbs behind a wide lens, and a burned out bulb may not be readily noticed, unless via side to side comparison. In this case the turn signal may appear to work, but the electrical current for that side of the car is reduced by about a third, causing unusual flashing.
Should you find all the bulbs seem to be working but one turn signal is dim compared to the other side, try turning off the hazard lights and turn on the parking lights. If that parking light is also dim, the fault is likely a poor ground connection for that lamp assembly. This is typically a wire connected to the vehicle body (metal) near the lamp housing. If the left and right parking lamps appear to be the same brightness, the fault may be a loose or corroded bulb socket, or faulty connection in the circuit leading to that turn signal.
Unusual turn signal operation can also occur due to an incorrect replacement bulb being used in one of the lamp assemblies. There are a bewildering number of bulbs in use, many of which look or plug-in similarly. When bulb shopping, be sure to compare the number (such as 7443) on the bulb or ask a parts pro to look up the application.
Q: My air conditioning stopped working. Are there things I can check, or how much should I anticipate spending to fix it?
A: Does your climate control system still blow (warm) air to all the usual places? If not, the problem could be the result of a blown system fuse, and the cause for this would require a professional's inspection. If air still blows but isn't cold, the fault is in the refrigeration portion of the system, such as a broken/missing compressor belt, severe refrigerant leak, or compressor circuit electrical fault. Beyond the belt, most of the likely fixes are unfortunately beyond the abilities of a home mechanic. Simply adding more refrigerant, via a do-it yourself kit is a bad idea unless the cause of leakage has been identified and corrected, and the specified total quantity of refrigerant can be verified. Repair cost, I'm sorry to say, is a wild card, as there are so many possible causes for failure. Plan on at least $200, and it could go substantially higher.
Brad Bergholdt is an automotive technology instructor at Evergreen Valley College in San Jose, Calif. Readers may send him e-mail at firstname.lastname@example.org ; he cannot make personal replies.