March 1, 2005

Rally-Pac WiringIn your Beyond the Basics column in the May '04 issue ("Help with PerTronix"), you advise Steve Kepley to "run a new wire from the Rally-Pac to the coil to achieve full voltage to the coil." I have a '6411/42 with a Rally-Pac and I understand your advice, but I need some clarification. Are you saying that, at the Rally-Pac, you splice in a new wire to the red/green wire (which comes from the back of the ignition switch) at the connector going to the Rally-Pac and run it to the ignition coil? Is this correct and is it easier than having to mess with the back of the ignition switch, which probably requires removal of the switch and moving the instrument panel out of the way? Can you recommend a gauge wire and any particular routing?Rich CarlsenPort Jefferson, NY

The resistor wire is wired in series between the vehicle's ignition switch and coil, so all the power flows from the switch, through the resistor, then to the coil. When a tachometer is added, it too has wires in series between the switch and resistor wire, so the power must flow through the tach, then the resistor wire and to the coil.

Mustangs without a tach have the pink resistor wire plugged into the red/green power lead you found on the back of the ignition switch. Eliminating the resistor is a simple matter of running a new wire from the red/green power lead to the positive side of the ignition coil.

Vehicles equipped with a tach have the pink resistor wire plugged into the black lead coming out of the tach. The red/green power wire is plugged into the remaining red lead on the tachometer. Eliminating the resistor requires running a new wire from the black lead on the tach to the ignition coil's positive side. As you can see, power flows from the switch, through the tach and out to the coil, then the new jumper wire. If you were to splice into the red/green wire, you would simply remove the tach from the circuit, as in the cars not equipped with a tachometer.

Routing the wire is not difficult. However, be sure it doesn't chafe through on any bracket or the firewall. A 12-gauge wire is adequate.

No GaugesI have a '69 Mach 1 with a 351W and a three-speed manual transmission. My instrument gauges (fuel, temp, oil, and alternator) quit working and the underdash wiring harness gets hot if the key is left on for a short period of time. The dash lights and turn-signal indicators work. I have replaced the gauges, circuit board, instrument voltage regulator, and wiring harness, and I cleaned the ground wire connection to the metal framework for the dashboard. Yet I still have the same problems. I don't know what else I can replace or repair. Do you have any ideas or suggestions?Bob BeckVia e-mail

Since you have replaced most of the parts that could have been bad, I have to assume you're simply not getting power to the gauge voltage regulator. The regulator is shared by all the gauges and, since they are all inoperative, I'd look for a common problem. With a 12-volt test light, carefully touch the contacts between the circuit board and voltage regulator. With the key on, the test light should illuminate continuously on one contact and blink slowly on the other contact. Be certain a good ground is maintained, as the regulator will not work without a ground. I believe you won't have power to the circuit board, and will find the plug between the underdash harness and circuit board to be troublesome. A steady light on both sides of the regulator indicates a faulty regulator

Do all your testing of the gauges with the key in the accessory position so the ignition circuit is not on

I wouldn't be concerned about the warm harness when the key is left on. I believe it's simply the pink resistor wire that runs between the switch and ignition coil. This circuit is not subject to a constant current draw as the coil is designed to be continuously turned on and off by the distributor points while the engine is running. Without the engine running, the coil remains on and the constant draw heats the pink resistor wire. To be sure, see if the harness cools down with a running engine.

Volt TestingI've changed my starter three times in the last two years, the ignition switch and ponytail, the voltage regulator twice and the starter solenoid twice. The battery is also new. The engine runs great for a month or longer and when I try to start it, the solenoid clicks as if the battery was dead. Could there be a problem in the harness?Ronnie SevinCanton, GA

When a Ford-style solenoid clicks only when starting the engine, the problem is usually traced to a lack of voltage reaching the solenoid, which can be caused by a weak or dead battery, as you mentioned, or a bad connection that creates some resistance to flow. Use a voltmeter to check the voltage of the battery to be certain it's at least 12.6 volts. Then check it again while a helper cranks the engine to determine cranking battery voltage. Connect the voltmeter to the battery ports, not the cables, in case the resistance is between the cables and posts. With the negative meter probe connected to the block, check for voltage with the positive probe at the battery-cable clamp end, battery-cable terminal end, and the solenoid terminal on both sides of the solenoid. In each test, the voltage reading should be within .5 volt of the battery while the engine is being cranked. Don't forget to also test the negative battery cable, as I frequently find battery cables with poor connections between the wire and terminal end.

Strutting Your StuffI'm in need of a pair of lower-control-arm strut rods. Both of mine are worn out (threads galled and a groove worn from a failed bushing on the other). I've had a difficult time locating a set. I've also been trying to find out if these parts are '67-specific or if similar pieces will work from a '68, and I'm getting conflicting answers from "expert" sources.

Will strut rods from a '68 work on my '67 big-block? Are these items reproduced? On every '67 I have located, they've been torched to get at other suspension parts or to ease disassembly. Do you know where I can get a set?Ron PeetersVia e-mail

New strut rods have not been available for a few years. However, many parts vendors can supply you with a set of reconditioned units. K.A.R. Auto Group lists all years of struts in its current catalog, which can be obtained at 800/341-5949 or www.karmustang.com.

You are correct, '67 strut rods are unique. However, '68-'73-style struts will bolt into your '67. The difference is in the steering stop area, as a '67 strut utilizes a separate plate to serve as a stop, similar to a '65-'66 unit. The '68 and newer struts incorporate the stop as part of the strut itself. Obviously, the '68-'73 strut is more readily available and cheaper to buy.

Temperature WarningI've run into a small but highly annoying problem with the restoration of my '71 SportsRoof, which was imported to the U.K. during its first year, then sold to the guy I bought it from some 22 years ago. I have since moved to New Zealand, but the ravages of salty English winter driving took their toll. The car is approaching the end of a six-year major restoration. Apart from some poor rust repairs and repaints, the car is virtually original and has never had anything replaced.