Q: I have a 2004 Saturn VUE. This winter the heater-A/C fan stopped working in position No. 1 but the other speeds worked fine. Now with summer here, the A/C only comes on in fan position No. 2 and not in Nos. 1, 3 or 4. If I fiddle with the speeds and the airflow settings the A/C light will randomly come on, flutter and go off. I can't discern any pattern. Thinking the fan speed switch was faulty I changed it but it didn't help at all. I do see there is a blower motor resistor that would be easy to change and there's an A/C relay somewhere. Any ideas?

A: There would appear to be two possible causes — the blower motor resistor block or the HVAC control unit. Guess which one is more expensive? So apply the KISS Principle — check the resistor block first. To do so, unplug its connector to inspect for signs of burned contacts. Probe each contact with a test light connected to battery voltage as you or a helper click the blower speed switch through each position with the ignition on. If the test light fails to illuminate on any circuit, check the connector and terminals on the HVAC control unit. If no problem is found, the control unit may be at fault.

If all contacts in the resistor block illuminate properly, no short to ground is found and the contacts aren't burned, the resistor block is the likely culprit.

Q: I have a 1963 Ford Galaxie 500 with a 289 V8 motor and two-speed transmission. A couple of buddies installed power steering on the car and while the belts were off the crankshaft pulley, we noticed about 1/3 of an inch of end play on the crankshaft. However, when the belts are on and the motor is running there is no noticeable in and out motion. I checked for shavings on the magnetic oil pan drain plug and filtered the used oil through a white T-shirt but didn't detect any shavings. There is no unusual noise from the motor which has about 36,000 miles on it since it was rebuilt. I put about 2,500 miles a summer on the car and have had no problems since we noticed the movement. An old school Ford mechanic told me that I need to have the thrust bearing replaced and could end up needing a new short block if the block has been damaged. I am 71 years old and retired so this expense would be painful. I am thinking that as it seems to be working fine and having no idea how long it has been this way, I may as well just keep driving it. What are your thoughts on this matter? What is the worst that will happen?

A: The worst that could happen? Your "old school" mechanic called it — damage to the block. One-third-inch of end play is roughly .333" — it should be less than .010". That much end play also puts stress on the connecting rod and bearings due to the slight misalignment of rod-to-crank at the limits of travel. If the crankshaft thrust washer wears completely through, the crank may begin to rub on the block and main bearing cap. The fact that you haven't found any magnetic debris likely means this has probably not happened — yet.

I'd suggest a compromise. At least drop the oil pan to inspect and measure the crankshaft thrust washer. If it is significantly worn or you see wear on the side of the block/bearing cap, it's time for an overhaul.

I have a small-block Chevy engine my son gave me that experienced this same problem, including slight damage to the block/bearing cap. I lightly sanded and polished the damaged area and replaced the crankshaft. Did it work? I don't know — I haven't installed the engine in by old C3 Corvette yet. Its original engine still runs reasonably well. But someday. ...

Paul Brand is the author of "How to Repair Your Car" and "How to Repair Your Truck and SUV," published by Motorbooks.