JBugs Video Series

1968-69 Beetle Wiring Harness Installation - Part 5:

Video Overview:

With all of our wiring now installed follow along as we test the electrical system to ensure all the electrical components are working properly and trouble shoot problems that arise.

Video Tips:

The tools you will need are:

Flat Blade Screwdriver
Phillips Screwdriver
8mm Wrench
13mm Wrench
Wire Terminal Crimping Pliers

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Click here for the previous video in our re-wiring series.

Video Transcript:

With all the wires in our new harness installed, and the battery hooked up. We can begin testing all of our switches, lights, and electrical components. Note that the knobs are screwed in onto the switches, and we have not installed the switches to the dash. This will make troubleshooting much easier if any problems do exist.


After installing new 8amp fuses at all of the terminals in the fuse box, turn the key on. With the headlight switch on at the first position, we can see the front running lights are on. Pulling the switch all the way back, turns on our low beams.


Reaching inside the car, pulling back on our turn signal lever, turns on the high beams. Pulling the lever back again, toggles the headlights, back to the low. Of course pushing the headlight switch all the way in, turns off the lights.


We can test the wipers by turning the wiper knob clockwise to the first position, which operates speed one on the motor. Turning the knob clockwise one more time, to the second position, operates speed two. After turning the knob counter-clockwise all the way, the wipers turn off and the wipers return to the parked position.


Pulling the emergency flasher switch operates the four-way flashers. The turn signals and the switch knob are all flashing as they should. Pushing the knob back in, turns the lights off.


Then we can test the left, and right turn signals.


Reaching inside and pushing the horn button does nothing. So we can test the horn itself by pulling the brown wire from the left front headlight harness, and touching it to ground. Doing that operates the horn, so it is getting power but not getting a good ground from the horn button. The horn and steering column ground is a common problem that we will troubleshoot later.


At the rear of the car, we can check the brake lights by pressing the brake pedal. The left brake light comes on, but the right does not so that is something we will have to troubleshoot in a moment as well.


Turning on the turn signals we have left, and right turn signals.


Shifting the transmission into reverse, turns on both reverse lights. Pulling the headlight switch to the first position, turns on the rear running lights, but the license light does not turn on. Looking at the rear license light assembly we can see that it has been swapped for a later model plastic housing which explains why the light doesn't work, it doesn't have a ground. We use a test lead to ground out the lens screw to the license light mounting screw and the light turns on. We will have a run a ground wire to the license light holder to make the light work. We do that with a short ground lead with a small ring terminal on one side, and with the license light lens and bulb holder removed from the assembly, feed the opposite end of the wire through the wiring sleeve at the assembly.


Then reinstall the bulb holder and lens. The ring terminal will mount behind the license light bulb holder, and will be held in place with one of the lens screws. Feed the wire through the license light assembly seal to the underside of the deck lid. From there we can install another ring terminal on the end of the wire, and attach it to the center license light assembly mounting stud under the nut. With the ground lead run, the license light bulb now works. Taking a look at the rear right taillight lens, we pull off the lens and take a look at the brake light bulb.

With an assistant pressing the brake pedal again, we wiggle the bulb in the housing and see that the bulb is working, when it is pushed against the metal housing. Pull out the bulb and unbolt the metal bulb holder from the taillight base. On the back side of the bulb socket, we use a small flat head screwdriver, and bend back the metal tangs of the base that contact the outside of the bulb. With the bulb back in the socket we have our assistant press the brake pedal again, and the brake light bulb is working so we can reinstall the bulb holder and the taillight lens.


Inside the car we can verify that the dome light works. In our case the up position works the dome light off of the door switches. With both doors open and pressing in the switches by hand, the light goes off. Releasing either switch turns the light on the dome light. Moving the dome light switch to the center position turns the light off. Moving the dome light switch to the bottom, the dome light turns on as it is in manual position.


At this point everything but the horn button is working properly, so we can disconnect the battery, and reinstall all the dash switches and brake light warning indicator. When installing the switches note that each switch has a notch on the threaded portion that sits against the dash. The dash sheet metal wall should have a small indentation that lines up with the notch to keep the switches from twisting.


After the switches are installed, disconnect the three wires from the brake light warning switch and feed them through the back side of the dash. The black wire goes to the 15 terminal, the brown to the 31 and the red to the K terminal. Then the switch can be pressed back in place on the dash. Now that all the switches are installed on the dash, reconnect the battery. We can turn the key on and we see both the oil pressure and the generator light bulb come on. Operating the turn signals, the left and right turn signals are working and the indicator bulb on the dash is working as well. Turning the wiper switch on we have low speed and high speed and the wipers go back to the parked position. Pulling the headlight knob all the way out we can see the speedometer illumination is on, (but hard to see in the video) Pulling back on the turn signal lever we can see the high beam indicator on the speedometer turn on. Pulling back on the lever again the indicator goes out and we can actually hear the relay toggling between the low and the high beams.


Also note that looking at the speedometer the fuel gauge has come up from empty, to just under 1/4 tank. Which mean the sending unit and gas gauge are working as well.


Lastly we can pull out the emergency hazard switch and see that the emergency flashers are working. With everything but the horn working we can start the car up, to make sure that the starter is hooked up correctly, and verify the dash warning lights go out, which they do. At this point the glove box can go back into place, the battery cables can be tightened, and the seats can be put back in place. Short of the horn, which we will troubleshoot in our next video as that can be a lengthy procedure, is working properly.