Like those sluggish windows addressed earlier, power windows can get bogged down with yuck and crud, rendering them slow or inoperative. Most of the time, power windows quit due to dirty connections between the motor and power lead. Sometimes, just jiggling the plug at the motor will get you back in operation. We suggest disconnecting the motor and cleaning the plug and terminal with television/radio tuner cleaner. This removes corrosion and crud, allowing electricity to flow again. Another problem is dirty brushes and armature, which make the motor quit for the same reason: no electricity flow. Clean the brushes and armature with tuner cleaner for the same results. As always, check the plug with a voltmeter or a test light to be sure you have electricity flowing to the motor.
Turn-signal switches rarely fail. But when they do, it can be darned inconvenient. Sometimes, it's downright frightening, especially when there's a semitruck bearing down on us. Why do turn signals fail, and what's the fix? Switches fail for a variety of reasons, mostly due to corroded or dirty contacts, which limit or stop the flow of electricity through the switch. Considering the location of a turn-signal switch--in the busy area inside the steering column and behind the steering wheel--failure doesn't surprise us. The turn-signal switch's contacts, which ride the steering-wheel slippery rings, get quite a workout. Dust, dirt, and crud find their way up the steering column from the engine compartment, adding insult to injury. Dirty contacts create resistance to the flow of electricity, which makes heat. And here's another one you probably haven't thought of: If you keep blowing fuses or cooking turn-signal switches, check and replace all of the turn-signal and parking-lamp bulbs. Bulbs sometimes short internally when their filament posts bend over from heat and short against each other. Check this first whenever you blow a fuse.
This isn't a common fix, yet it should be anytime you build an engine or do a valve job. Hardened exhaust-valve seats are a must if you drive your Mustang a lot or do a lot of hard driving. Prior to 1972, Ford's engine valve seats were made of iron, which worked just fine when gasoline still contained lead. In fact, they were little more than a machined-iron surface in the iron cylinder head. Hardened valve seats are separate steel inserts that are installed in the cylinder head during a valve job. If you trailer your Mustang or drive it rarely, don't sweat the hardened seats. Your money is better spent elsewhere.
24 Battery Apron Rusts Out
Battery acid is hell on anything it touches. This is why inner-fender aprons and battery trays rust out with regularity in older Mustangs. You can replace the inner fender and battery tray, or you can cut and patch using a reproduction apron. A good rule of thumb with rusted-out battery trays and aprons is to protect the new steel with a good self-etching epoxy primer/sealer. Then apply several thin coats of satin black. For sheetmetal information, contact National Parts Depot, Dept. MM, 900 S.W. 38th Ave., Ocala, FL 34474, 800/874-7595, www.npdlink.com.
Have you ever moved the climate-control switch to HEAT and had cold air in your face instead of warm air on your feet? What about that 95-degree day last summer when warm air blew from the outlets because the A/C compressor wouldn't engage? Your Mustang's in-dash A/C system ('67-'73) operates with engine manifold vacuum to move its air doors and hot-water valve. Slide the selector to FRESH and you're bringing in outside air, coupled with air-conditioning compressor engagement for cooling. Slide the knob to MAX and you close off outside air, recirculating cabin air, with the air-conditioning compressor engaged. Go to HEAT to direct fan air to your feet. Slide the TEMP knob, and you direct vacuum to the hot-water valve, allowing hot engine coolant to circulate through the heater core. DEF (Defrost) moves the doors to direct hot air to the outlets on top, defrosting the windshield. A/C is also engaged in DEF mode, which helps dry the air. Proper operation of the vacuum-operated doors and hot-water valve relies on vacuum hoses that are connected properly. When these doors aren't opened or closed when they should be, your Mustang's climate-control system isn't going to work properly. Consult a vacuum diagram and connect your climate control's vacuum hoses properly. To get a vacuum schematic, a Ford shop manual, or a Mustang assembly manual, contact Jim Osborn Reproductions, Dept. MM, 101 Ridgecrest Dr., Lawrenceville, GA 30045, 770/962-7556, www.osborn-reproduction.com.