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Painless Performance Harness Installation in '39 Ford

Installation of a Painless Performance Wiring Harness in 1939 Ford
39 Resto Wiring  by Dennis Overholser,  Painless Performance

Popularity of old school rods is becoming more prevalent with each passing day. The older the owners become, the more they want it as it was in their youth. Bob Burks, of Ft. Worth, is no different. When he acquired his 1936 Ford sedan, there was no doubt that it was going to be rebuilt back as close as possible to original. 

Reversing the eyes on the springs, repainting the exterior and interior as well as  re-upholstering the original seats was tasks that seemed not to require a lot of thought. Bob soon found out that re-wiring the car may be a bit different since he wanted the dash and the rest of the electrical system to look basically stock while changing over from 6 volt to a 12 volt system. The main challenge was the ignition switch, light switch and starter button. The rest of the wiring could be hidden or covered, but the dash, which was re-wood grained, had to look stock.

A visit to some friends at Painless Performance provided Bob with the necessary information and diagrams needed for the re-wire of the 39. He found that by using relays he could retain the stock ignition and starter switches. The light switch, which is a new aftermarket unit, has the look of the original but can replace the old switch and the dimmer switch. 

When the word got out that Bob was going to do the re-wire several friends came by to help. In the course of a weekend the car was re-wired and ready for a road test. Except for a few wires under the hood, no one would ever know it wasn’t original
10101   This photo shows the universal style lit often used in re-wiring street rods and custom application vehicles.  Painless, the innovator of this style kit provides all the needed wiring to do the job.
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Bob Burks, for safety, removes all jewelry before starting the re-wire of his 1939 Ford.   Sergio Rodriguez looks over the instruction manual before starting. A wealth of information is in all of the manuals printed by Painless. Lost your manual? Painless offers all their manuals on their website
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Sergio holds the fuse block mounting plate in position and marks the mounting holes to be drilled using the bolts holding the oil filter to the firewall. This will make a perfect place for the bracket.   The mounting bolts, included in the kit for the fuse block, were welded to the bracket, making studs, which will allow for easy mounting and removing of the fuse block. The bracket was then repainted before installation.
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The oil filter bolts were replaced with ½” longer ones to allow for the thickness of the bracket and locknuts.   With the bracket in place, the fuse block is installed on the studs and furnished nuts are installed and tightened.
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Bob, in the meantime, installs the new 12 volt starter solenoid. An ignition coil bracket was also fabricated which will mount the new 12 volt coil to the front drivers side of the engine.   Sergio now starts separating the different groups of wires in the harness. The three main groups are for the dash, engine compartment and the tail of the car.
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All the wires in the Painless harness are color coded as well as printed with the destination of each wire. This aids in the installation as well as troubleshooting later if the need would ever arise.   The decision was made to route the firewall forward wires through on the passenger side due to space limitations on the drivers side. A hole was cut for the rubber grommet furnished in the kit.
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Clamps were installed on the inside of the firewall to hold the harness in place. Not allowing the harness to hang or flex will lengthen its lifetime.   Sergio can now start pulling the wires through the firewall. Care should be taken to prevent kinking of the wires when pulling them.
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Separating the wires for each headlight, turn signal and the engine are next. They will be carefully routed to their destination avoiding hot spots and sharp edges.   Bob drilled a hole and installed a grommet for the brake light wires on the drivers side lower firewall. 
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Bob now uses the furnished tie wraps to make the wires into a small harness for easier routhing to the switch.   The break switch wires are attached to the wires and connector that came with the new Painless low pressure brake switch.  The wire colors were designed to match for a simple installation.
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edges. John Roberts helps by taping the tail wires to the floor.  Care is taken not to route them nea the sear mouths or another opening in the floor.  Combing the wires will also help prevent lumps in the carpet.   With all the wires routed to the rear, Bob Boudreaux drills holes for grommets to allow the tail light wires through the inner rear fenders.
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The yellow and brown wires for the turn/brake and tail lights are routed through the left inner fender and the green and brown are routed for the right brake/turn and tail light. The license plate light will get power from the rights side tail light wire.   Bob pulls the wires through the tail light opening and prepares to cut the wires to length.
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Bob installs bullet style terminals on the tail light wires so the lights may be easily removed later for servicing.   The last wires in the tail section to install are the fuel tank sender and optional electric fuel pump. Note the ground wire attached the body of the fuel sender; it is routed over to the frame and attached.
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While Bob is finishing the tail, John separates the dash wires in preparation of installing the dash gauges and switches.   The light switch is wired first. It has 4 positions, off, park and tail, low beam and high beam. No dimmer switch is required with this style switch.
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The starter switch only requires a single wire so a ground wire, which activates a relay, was attached. The relay, which will be explained more later, activates the starter solenoid on the fire wall when the starter button is depressed.   John now prepares the wires for the gauge clusters. The chassis harness comes with all the gauge wires as well as the power wire. A short ground wire will be made and attached to insure proper gauge functions.
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Adapter terminals were placed on the studs first, then wires are attached to the gauge cluster with push on terminals. These terminals, of which we had some left from a previous job, come in the universal dash harness kit form Painless.   The ignition switch, shown, is like the starter button. It will require relays to be able to power up the different circuits in the fuse block. This switch will now become a switched ground for relay activation.
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The back side of the switch reveals 2 terminals. Originally one was battery input and the other was power out. Now one is tied to ground and the other goes to the ground terminals of the ignition and accessory relays.   Three relays were mounted under the dash. One for the starter activation, one for ignition power for the fuse block and one for accessory power to the fuse block. Input power for the relays comes from the main input power wire to the fuse block from the maxi fuse.
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The completed installation of the relays. Note the buss bar at the top where all the relay power wires come in from the bottom and the large wires at the top is the input wire cut in half and both ends attached.    The final interior item was the dome light. The original was cleaned and remounted to the door post.
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The original dome light switch was wired with the harness constant hot wire. Bob decided he wanted to retain the original look and did not add door switches.   While everyone else was working on the inside, Sergio was mounting the Maxi fuse to the firewall. This fuse protects the overall electrical system. The Maxi fuse also makes a good junction point.
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The head light pigtails were spliced on to the harness wires after the were cut to length..   The turn signal socket was removed and a ground wire was attached. The extra ground will insure the proper operation of the light in case the fender would lose it’s ground.
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The light socket was re-installed and the power wires were spliced in. The light assemblies are now ready for re-assembly.   Next the engine coolant temperature sender was wired. This wire goes directly from the sender to the gauge in the dash cluster.
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The oil pressure sender was wired in the same fashion as the coolant sender.   Battery cables were made and attached to the starter solenoid. The solenoid activation wire from the relay under the dash was also attached. The ignition bypass terminal on the solenoid will not be used in this application.
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A bracket was fabricated and a conventional style coil was mounted. The ignition power wires as well as the wires to the new MSD distributor were then attached.   A small battery charger was hooked to the battery cables. This will allow enough current to power any one circuit without damaging any circuit if there was a problem.
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Each circuit is now activated to insure proper operation. Once all the circuits have been checked, the battery cables will be installed permanently.   Bob stand out side if the 39 and fires the engine. All systems are go.
Photo 67   test This article was provided bu Painless Performance. 
With the car now wired, the interior still looks completely stock. Some floor boards and we will be ready for a test drive.    


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