This looks painful, right?...
This looks painful, right? Well, once we removed the stock harness from its 26-year-old home, our big headaches were all but over. Short of some time-consuming soldering, the rest was a breeze.
Though we vowed to have dyno numbers for you this month on our True Street project, we’ve been a little tied up. Actually, we’ve been working hard on Repeat Offender and time slipped right through our hands.
What we were able to finish this month will be helpful. The massive stock wiring harness was chock-full of useless systems and a sticky varnish that apparently could only be removed from our hands with kerosene; the battery cables were in the engine bay and we needed them in the trunk; and with our soon-to-come MSD ignition system, the stock ignition wiring was useless and in the way.
If we were building a typical track-only car, the electrical system could remain somewhat simple and basic. We could just run a few wires for the necessities like fuel pump, fan, gauges, ignition, starting, and charging. However, when building a car destined for the street, the complexity of the electrical system grows significantlyespecially if you want to maintain creature comforts.
The key to our automotive...
The key to our automotive wiring liberation was the assortment of products seen here from Painless Performance Products. The main chassis harness is just under $600, but we couldn’t resist adding all the goodies that Painless offers, like a triple-relay harness, its PowerBraid wire wrap (in three different sizes), and a high-output alternator wiring harness. After tax and shipping, our kit was close to $1,000.
Something else to consider is the condition of the original harness. Our car, for instance, is over 26 years old. There’s a good chance there is either corrosion in the harness or Father Time has made the old insulation brittle. Either way, we don’t want to take any chances.
If you choose to keep your original harness, make sure it’s safe and functional before proceeding with a project such as oursespecially when powering demanding components such as a high-volume fuel pump or electric water pump. We had to make the decision to just deal with the factory harness for its all-inclusive ability (with risk), or exchange it for a more simple harness that may or may not have everything we need. Enter Painless Performance Products.
Painless has been leading the automotive wiring industry for 21 years, and you’ve undoubtedly heard of its products for street rods, custom cars, and racing applications. Though many of its products are generic, Painless also makes manufacturer-specific harnesses for various GM, Mopar, and Ford models.
The chassis harness that we chose (PN 10123; $596.89) is a four-circuit universal Ford musclecar harness built to fit most Ford cars from ’66-’76. However, since Ford has kept most of its wiring colors the same throughout the years, most will match our ’85 LX harness perfectly. The harness has provisions for everything from lights to wipers, and the horn to the radio.
The first step is to remove...
The first step is to remove the main factory harness. It unplugs from everything in the column and pulls through the firewall from the engine side.
Since we want our harness...
Since we want our harness to be hidden as much as possible, we looked under the left front fender for a hidden route. We found a hole large enough for our harness and removed the plug.
Beginning under the dash,...
Beginning under the dash, we placed the fuse panel where it will be permanently mounted and ran the necessary wires through our new-found hole with a grommet.
Painless also sent us its PowerBraid tool kit (PN 70941; $68.95), which allows quick and easy installation of its PowerBraid wire wrap, of which it also sent us an assortment. We also requested a three-pack relay bank (PN 30107; $148.20) to power our fan, electric water pump, and a spare for future use.
We then used the Painless...
We then used the Painless PowerBraid tool to apply the wire wrap.
The Painless wiring harnesses feature a lightweight design and protection against overload well beyond what the factory harness can offer. All of the wires are colored, labeled, numbered, and grouped into different sections to make routing easier. There’s no doubt that installing a new wiring harness is a complex and time-consuming task (at least 40 man hours), but Painless makes it as simple as possible.
To power our harness, we chose a top-post Dyna-Batt (PN 5575B; $119) from Performance Distributors. At 13.5 pounds, it’s over 20 pounds lighter than a standard battery, and will mount almost anywhere with the Dyna-Batt bracket (PN 5475; $79). We decided to mount ours in the trunk, next to our Flaming River remote battery-disconnect switch (PN FR1003-2; $93.45).
With our original harness...
With our original harness laid out on the shop floor, we scoured it for connectors that we needed to attach to our new harness. Simple as this may seem, you may want to label these before removing it from the car—it will save you some time…just saying.
Elsewhere, we tied the Painless harness to our new MSD 6AL-2 ignition control (PN 6421; $279.99) and AutoMeter gauges. The 6AL-2, the newest version 6AL, has a built-in two-step rev limiter with rotary dials, accepts almost any crank trigger, and features digital controls.
The gauges, Auto Meter’s Competition Series, feature programmable high and low warnings, which can also be wired to warning lights, fans, or alarms. Prices range from $139.99 to $299.99 through Summit Racing Equipment.
We also installed a 150-amp alternator (PN 7771B6G) by Tuff Stuff Performance. This black-powdercoat alternator features an internal voltage regulator and retails for $179.95 through Summit Racing Equipment. We also received a 400 Series starter from Meziere (PN TS408; $544.50).
The next, and most time-consuming,...
The next, and most time-consuming, task is to match the new harness to its proper pigtail or component.
The most efficient way to...
The most efficient way to do this is to have one person reference both a factory wiring diagram and the booklet that Painless includes with the wiring kit.
Match the wires to be attached...
Match the wires to be attached and cut, strip, and solder the ends together. You can use butt connectors for this (which are included in the kit), but soldering makes a cleaner and more reliable finished product.
Then slide heat-shrink over...
Then slide heat-shrink over the soldered joint and heat.
When each harness is finished,...
When each harness is finished, tape where necessary and secure in place.
Under the hood, we installed...
Under the hood, we installed a new oil pressure sender and coolant temp switch, both of which came with our new Auto Meter gauges. Each sensor comes with its own harness, which connects directly to the back of the appropriate gauge.
Our 150-amp alternator from...
Our 150-amp alternator from Tuff Stuff Performance was then mounted in place.
Our starter from Meziere is...
Our starter from Meziere is a 400 Series and is made for 157- and 164-tooth Ford applications. It features a billet aluminum mounting plate and 360-degree clocking in 10-degree increments.
To run the needed wires to...
To run the needed wires to the rear, we attached the end of the new harness to the old harness with electrical tape and pulled gently until the new harness was in the trunk.
We then attached the ends...
We then attached the ends to the proper pigtail on the lamps and ran a spare key-on wire to a relay for the fuel pump. Since we mounted our Aeromotive A1000 pump near the front of the fuel tank, we simply ran the fuel pump wires through an existing hole in the trunk floor.
Flaming River sent us this...
Flaming River sent us this remote battery cut-off switch. It is necessary to be NHRA-legal when relocating the battery.
Against his better judgment,...
Against his better judgment, former MM&FF Tech Editor Steve Baur took the Snap-on air drill to his left-hand taillight lens and “blew a hole in it,” as he likes to say.
Prestolite Performance sent...
Prestolite Performance sent us a roll of battery cable from its Accel brand. It also sent us the appropriate cable ends to attach to our battery and shut-off switch.
As you tighten the terminal,...
As you tighten the terminal, it squeezes onto the wire.
Here is our trunk wiring completed....
Here is our trunk wiring completed. As you can see, we applied heat-shrink tubing to our battery cable ends as well.
Our MSD 6AL-2 programmable...
Our MSD 6AL-2 programmable digital ignition controller mounted cleanly to the kick panel under the driver’s side of the dash. From there, we’ll run the wire through the dash that can connect it to a laptop.
We mounted the three-pack...
We mounted the three-pack relay bank under the hood. It will power our cooling fan and water pump, with one to spare for future use.
To fit our gauges, we had...
To fit our gauges, we had to slightly modify our instrument cluster bezel. Baur insisted on keeping the wood grain, and now we’re glad he did.
Our Auto Meter Competition...
Our Auto Meter Competition series speedometer and tachometer gauges mounted easily to the front half of our original instrument cluster less the clear plastic lens.
The fuel level, oil pressure,...
The fuel level, oil pressure, coolant temp, and battery voltage gauges mounted to the wood grain bezel in the stock position with a less-than-original mounting style
The finished product speaks...
The finished product speaks for itself. Though we would have liked for the smaller gauges to be recessed like the big ones, the new cluster still has a factory look. The best thing about the new gauges, though, is their programmability and accuracy—not so with the stock analog gauges.