Wiring issues - related?

[70Crew]

Before I reinstall my windshield I want to make sure all the electrical parts and pieces are working. I’ve traced back several non-op bits successfully but am left with a couple I can’t easily figure out. Can you take a look at this list and offer any suggestions, either (i) that some are related, or (ii) how to troubleshoot each issue individually? Anything I haven’t mentioned is functioning as it should, although I have not yet installed the dome light.

1) Back-up lights are non-op. I did replace the fuse next to the coil.

2) The high beam headlight flasher doesn’t work.

3) The right front turn signal is dramatically brighter than the left side and the right flasher also does not work. I pulled the lenses. On the right (bright) side, the longer filament is lit continuously. On the left side it is the shorter one that is lit continuously (the longer filament flashes).

4) All the dash lights (including the radio) work when I turn on the parking lights. When I turn on the headlights, the dash lights go off.

See any pattern here? If not, I have a multi-meter but not a lot of experience, any specific troubleshooting instructions would be much appreciated!
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1970 Crew Cab

[sjbartnik]

Nope, you've got 4 separate problems to trace out.

The reversing lights is the easiest circuit, maybe start there to build confidence or leave that one for last because it's easiest.
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[70Crew]

One down, 3 to go. The front turn signal issue (#3 on my list) was that the two wires on the fixture were crossed.... Who knew they were not interchangeable? I saw that in an old forum post.

Started in on #2. Checked all the connections at the fuse box to make sure they are tight. Traced all the wires to make sure they are plugged in to the correct terminals. I don't know how to bench test the relay (is it possible?) but I did have another matching relay that I tried with no success. The second relay could also be bad but they are both OEM and clean so I am guessing not. Tomorrow I am going to try hooking up another turn signal switch to see if that makes a difference.
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1970 Crew Cab

[telford dorr]

Bench-testing a headlight relay:

You need a source of 12 volts, some clip leads, and a 12 volt test light. Note: -12 volts = ground.

The relay has terminals 56, 56a, 56b, and S. If it's a Euro style flashing relay, it also has a 30.

Connect 12 volts to terminals 56 and 30. Touch S to ground. The relay should click.

Connect a test light from 56a to ground. Touching S to ground should toggle the test light on and off.

Connect the test light from 56b to ground. Touching S to ground should toggle the test light on and off (but opposite from 56a).

If your relay has a terminal 30, then:

Disconnect the +12 volts from terminal 56. Leave +12 volts on 30. Connect the test light from 56a to ground. When S is grounded, the test light should light, and go off when S is ungrounded.

Note: if you don't have a terminal 30, the headlight flash function won't work.
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'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[scrivyscriv]

dash lights.. you probably have the dash lights on the wrong terminal of the headlight switch.. should be plugged into terminal 58b, and your 'parking light' lamp should be on terminal 57
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Robert in Memphis
Dünkelgrügen 1967 Java Green bug thread
Engine rebuild thread
If you're ever in the Memphis area, you are welcome to stop by for advice and help.

[sjbartnik]

Another thing to check for the headlight relay is the switch to ground in the turn signal switch. The headlight relay is a latching relay that flips outputs when grounded and hold that state until grounded again.

The grounding is accomplished at the turn signal switch. Verify with your wiring diagram, but typically there is a brown/white wire from the relay to the turn signal switch. Then a solid brown wire coming out from the turn signal switch to a ground point under the dash. When you pull the lever for high beam all you're doing is connecting those two wires.

So if the brown wire is not properly grounded, the relay will not function and nothing will happen when you pull the lever for high beam. So check for that ground before you go swapping out turn signal switches.
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[70Crew]

I do love me some Samba. Where would I be without you guys (still in the garage, no doubt).

Three down, one to go.

#2 - sjbartnik, you were dead on. I traced the ground back to a connector that had separated. Also thanks to telford dorr for the detailed bench test instructions that even a newbie like me could follow. As it turns out, my original relay was good and the second one I tested was bad. High beams now work great.

#4 - scrivyscriv, you were also dead on. However, it was interesting why it happened and I wanted to share that with everyone as a warning. Back when I started this project I ordered a laminated electrical diagram off of EBay which I have been using pretty regularly. When I saw your note, I went back and compared the laminated version to the one in Bentley. As it turns out, the laminated diagram has 57 and 58a backwards.

Now off to the backup light troubleshooting. Any suggestions (I checked the fuse in the engine compartment)?
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1970 Crew Cab

[sjbartnik]

Backup light is the easiest one (I shouldn't jinx it)

Power comes from the + terminal at the coil. You found that already with the fuse holder. Do make sure that it's plugged into terminal 15 of the coil (which is pos.) and not terminal 1 (which is neg.).

Then follow that black wire under the bus where you will find it going to a switch installed on the transmission. The switch is very simple, 2 terminals. Power comes in on one terminal (doesn't matter which one). When you shift into reverse, a doohickey inside the transmission pushes on the switch which connects the two terminals electrically. Power then flows through the switch out the other terminal and back to the lights. There should be a T in that part of the circuit somewhere for the single wire coming back to split and go off one to each side.

Check that you have power to the switch with key on and check that you have power coming out of the switch with trans in reverse.

If that's all good then trace the wiring back to the lights, you'll find the problem in there somewhere.
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[Starbucket]

Remove the bulbs and clean all contact areas and inspect the bulb filament. Sounds like a no brainer but I bought a 57 Karman Ghia and only 1 headlight with only 1 beam and 1 tail light and no brake lights, and you guessed it, it was all the bulbs had burned out over the years.

[70Crew]

[70Crew]

4 for 4. That was more involved than I expected but sjbartnik's suggestions did the trick. I ended up repairing the fuse holder, soldering 2 wire breaks, and replacing a burned out bulb.

Life is good.
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1970 Crew Cab

[sjbartnik]

SWEET!

(I knew I shouldn't have jinxed it by saying that the reverse lights were easiest)
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650