Weak link: HVAC airbox under dashboard
Models affected: '74-'93 Ramchargers and pickups
What happens: The airbox that houses the AC evaporator, heater core, fan motor, and fan speed resistor is mounted under the passenger side of the dashboard. Its design allows small litter to be ingested, thereby blocking airflow through the heater and cooler. Not only does this affect the performance of the heater and air conditioner, but it's also a fire hazard. The air-cooled fan speed resistor gets hot when on low/medium speed, and since litter can adversely affect the airflow, the resistor can overheat and start a fire. Further, any litter that comes in contact with the resistor can also potentially start a fire.
Sturdy fix: Carefully cut an access hole in the airbox using a rotary tool or jigsaw. Make sure you don't cut too deep. Clean the inside of the airbox using a vacuum cleaner and a semi-soft brush. When you're done, make a patch panel from a small scrap of sheetmetal to cover the hole you cut and seal the new patch with silicone. To keep junk from falling into the airbox, cover the air inlets with screening.
Contact: Do-it-yourself fix.
Weak link: Poor wiring design at the bulkhead connector and ammeter
Models affected: '80-and-older trucks and SUVs
What happens: Full alternator current passes through a poorly designed bulkhead connector to the dash wiring, then to the ammeter, back through the bulkhead connector, to the starter relay, and finally to the battery. Over time, the heat caused by the full alternator current going through the resistance of the connectors can cause the bulkhead connectors and wire to melt and possibly cause a fire.
Sturdy fix: The hot ticket is to eliminate the poor factory system altogether. Mark Hamilton from Mad Electrical has created a very impressive fix that eliminates these inherent problems. It also eliminates the ammeter and replaces it with a much more useful voltmeter to monitor the charging system. For a complete overview and step-by-step instructions of the procedure, visit the following Web site.
Contact: Mad Electrical, www.madelectrical.com/electricaltech/amp-gauges.shtml
Weak link: Steel sleeve in sport mirrors
Models affected: '88-'93 trucks and SUVs
What happens: The steel sleeve used to keep the mirror head fixed wears out and allows the mirror to flop.
Sturdy fix: Remove the housing with a Torx bit to gain access to the mirror clamp, taking care not to damage the rubber seal. Buy a plastic shower curtain sleeve and cut approximately 2.5 inches off the end. This new end can be used as a replacement for the worn-out steel sleeve.
Contact: Do-it-yourself fix.
Weak link: The front pump in the 727 automatic transmission
Models affected: All vehicles equipped with the 727 automatic transmission
What happens: The transmission front pump drains fluid from the housing during long periods of sitting without use. This causes slippage during cold startup and engagement. It can actually take a few minutes to get the transmission pump primed before it fully engages.
Sturdy fix: With the transmission removed, pull the front pump and reseal it with anaerobic sealer. This will prevent fluid drainback when not in use.
Contact: Do-it-yourself fix.
Weak link: Windshield-wiper arm bushing
Models affected: '74-'93 pickups and SUVs
What happens: There's a plastic bushing in the windshield-wiper linkage and it dry rots, resulting in breakage. When this happens, the wiper linkage falls apart, causing the windshield wipers to fail.
Sturdy fix: Many auto parts stores sell the replacement bushing. We hear that they're also available in those neat little Help packages found in places like Auto Zone. The bushings are also available from your local Dodge dealer. An even cheaper fix is to remove the linkage from the vehicle and drill a small-diameter hole in the pivot points and then install washers and cotter pins.
Contact: Your local Dodge dealer or www.autozone.com
Weak link: Central Axle Disconnect (CAD)
Models affected: '85-'93 1/2-ton trucks and SUVs, all '94-'01 trucks
What happens: These vehicles use a vacuum motor to engage the front axle when four-wheel drive is selected. Unfortunately, these motors often fail, leaving the four-wheel-drive system inoperable.
Sturdy fix: If you've had it with this system's imperfections, and you own an '85-'93 model, you can install manual hubs and lock the CAD unit. To lock the CAD unit, remove the CAD vacuum motor. When you reinstall it, don't engage the shift fork between the e-clips. Instead, slide the fork all the way out and install the farthest clip so that it pushes on the fork. Another option is to replace the CAD unit with a 4x4 Posi-Lok system that allows you to manually lock the front axle by simply pulling on a cable (shown).
Contact: 4x4 Posi-Lok, 517/279-7177, www.posi-lok.com