, Salem, MA

June 8, 2013

Driver can't get heat, AC controls to work

Auto Scanner
Larry Rubenstein

---- — Q: I was recently driving my wife’s 2002 Toyota Camry and I could not control the heat or turn on the air conditioner using the dash manual circular temperature control. The auto has 59,000 miles, and is a six-cylinder with an automatic transmission. Is it an easy or expensive fix? Is it the dash controller or the radiator thermostat? Your best price estimate, please.

A: With the information you give me I can only tell you what it isn’t. It is not the radiator, it is not the thermostat. The problem could be as simple as a blown fuse or as costly as a wiring harness. Your best bet would be to drop the vehicle off at a repair facility that uses the ALLDATA information system to trace the problem to the source. Be sure to tell the facility to call you with a price estimate of the repair before making the needed repairs. You should know that whether you decide to make the repairs or not, you are still on the hook for the diagnostics.

Q: Recently the lamp monitor in my ’94 Buick Park Avenue indicated a defective tail light. I have checked them all out and all are working properly. My guess would be that there is a bad ground connection someplace, given the age of the car, but I am told the ’94 Park Ave has only one grounding point for the entire lamp monitoring system, which is located on the driver’s side bulkhead. If this is the case, wouldn’t all the monitor lights be acting up? Any ideas on where to look for a single tail light indication error? I look forward reading your tips and advice every week in the Salem News.

A: First thing I would look for is traces of water in the tail lamp assembly. Next, see if the monitor shows a bulb out with the trunk open. The wiring harness from that year is very fragile and due to the age, it may be splitting.

Q: I own two ’02 Grand Cherokee Overlands with 4.7-liter, eight-cylinder engines, and both make a groaning noise. One car is in Florida and the other here in Massachusetts. The Jeep in Florida we had diagnosed by a rear-end specialist. He concluded it was the clutches in the differential. They are made of paper and the bridle assembly can’t be taken apart to replace clutches. Even though the gear assembly was in great shape, the only remedy was to change the whole bridle assembly. He assumes this is why Jeep adds the gear additive to differential fluid. The fix cost me $1,100. That was the cheapest estimate I could find. Chalk it up to planned obsolescence from the auto industry.

A: It’s unfortunate for sure. This is a common problem with this particular vehicle, but the problem can be avoided. Proper maintenance calls for servicing the rear and front differentials at particular intervals. For an all-wheel drive vehicle, I recommend a differential service at 30,000-mile intervals. And the manufacturer’s recommended gear oil and additive of course needs to be used as well. Because the clutches are so thin on your vehicle, once the fluid gets gritty it does not take long to wipe them out.


Larry Rubenstein is a master technician who owns a North Shore service station. His column appears every Saturday. Write to Larry at The Salem News, c/o Auto Scanner, 32 Dunham Road, Beverly, MA 01915, or send an email to