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Ford Mustang Beyond The Basics
Vintage Mustang Tech Advice From Bob Aliberto
The March 2010 issue has a nice question and answer regarding wiring for the PerTronix electronic ignition conversion. I would like to share one item that a lot of people forget.
Once you unplug the pink resistor wire at the dash, you have an exposed male bullet connector end. If you are using the stock starter solenoid, the "I" terminal ties into the resistor wire at the firewall connector. When you start the car, battery voltage passes through the "I" terminal to the coil for the points, which are no longer used with the PerTronix conversion. This voltage can back-feed through the resistor wire to the above mentioned bullet connector. If it is not taped up, you can have a direct short.
When I installed my PerTronix, I removed the connector on the "I" terminal since it is not needed with the electronic ignition components. I simply wrapped it up so it cannot be seen.
You are absolutely correct that the pink resistor wire would be hot while the engine is cranked. Should the bare bullet connector come in contact with metal, then a direct short would occur. Simply removing the wire at the "I" connection on the solenoid or taping the bare bullet connector - or both - will eliminate the problem.
As illustrated from this example, all loose wire ends must be taped up securely on any automotive project. Just as any firearm should be considered loaded, all wires should be considered potentially hot and therefore insulated.
I have a '66 Mustang with a 289 and 4-speed. The engine has '83 Windsor heads, original distributor with PerTronix electronic ignition, new Edelbrock 600 cfm carburetor, and Autolite plugs gapped at .044. The car runs good but something doesn't seem right because I can always smell unburned fuel. Any advice would be appreciated.
Via the Internet
This is a common occurrence when a high-performance carburetor is added, particularly with the installation of a performance camshaft as well.
The carbs come from the manufacturer with a rich setting to minimize the chance of ruining an engine with a lean mixture. The Edelbrock carb is quite tunable with a calibration kit that contains an assortment of metering rods, jets, and step-up springs for the power valve. Since your engine runs well otherwise, I'd suggest fine-tuning the carb idle mixture with the use of the calibration kit. It will require some patience because it's a trial and error procedure. However, the kit includes detailed instructions and usually provides excellent results.
I'd like to upgrade the headlights on my '67 Mustang but without spending the money for an H4 kit. Can I install over-the-counter sealed-beam halogen lamps, such as the Sylvania H6024ST or H6024XV, without overloading the wiring?
Sealed-beam halogen lamps can be used in an early Mustang with the existing wiring harness as long as the harness and all of its connections are in excellent condition. The halogen bulbs do not draw enough to overload the circuit unless there is a loose or corroded connector. Pay particular attention to frayed or loose wire terminal ends at the headlamp plugs and ground connectors. Be sure to check the dimmer switch under the carpet as it can be easily overlooked.
The stock wiring can handle the halogen sealed beams but the headlight switch cannot. Early Mustang headlight switches, with their 12-amp circuit breaker, deteriorate over time and often fail even with stock lighting. The switch should be replaced with one from a four headlight system, such as a '69 Mustang or Cougar, because it incorporates a higher amp load breaker. I've found that a Standard Products' switch, part number DS148 with a 22-amp breaker, works well. It's available at my local parts store, and the part number can be cross-referenced to other brands as well.
I have used this set-up many times over the years with sealed-beam halogen bulbs. However, more powerful or off-highway bulbs that draw more than sealed-beam units will require a relay to protect the wiring.
Front or Rear Sump?
I am installing an '81 5.0L/302 engine in a '68 Mustang. The oil pan appears to be a dual sump, although the pick-up that came with it looks like a rear sump. My question is, will this oil pan clear or do I need to get an oil pan with a front sump and pick-up?
The '68 Mustang chassis, with its center crossmember and steering linkage, will interfere with the dual sump oil pan. You will indeed need to use the early-style front sump pan and pick-up. Some 5.0L engines have the dipstick in the oil pan, so be certain you have a provision for the dipstick in your timing cover.
Send your '65-'73 Mustang questions to: Beyond the Basics, c/o Bob Aliberto, P.O. Box 205, Salt Point, NY 12578. Send email to firstname.lastname@example.org.