Electrical issues, Help!! Options

[gklinger]

I've got some strange electrical things going on.

Symptoms:

Brake warning light always on.
When brakes are applied, light goes out momentarily then comes back on.
When turn signals are activated, turn indicator flashes (left or right) correctly, but brake warning light flashes along with turn indicator.
Flasher relay makes a very slight buzzing noise, can only be heard when the car is not running, but I'm sure it's always there. New relay does the same thing.
Instrument lights are always on.
Rear license plate lights always on.
If the car is running and the light switch is in either parking or headlight position, and the ignition is switched off, the car continues to run as if the ignition were still on. If lights are then turned off, the motor is switched off.

All lights operate normally otherwise. Car is a '73.

This has really got me stumped. I'm wondering if a bad headlight switch may be responsible? This just started out of the blue one day, hadn't done rewiring or anything to cause it. Anyone have any ideas?

[grasshopper]

wow.....you have issues (IMG:http://www.914world.com/bbs2/html/emoticons/ohmy.gif) ...........

[bd1308]

start checking wire for chafing and check your connections for crossing....

i bet your drawing ign power from your headlights area.

happened to my car.


b

[lapuwali]

There are enough terminals and weirdness that I'd not be surprised if a short in the headlight switch couldn't bridge two circuits that would even include the ignition.

Here's how I'd start: Pull the switch (knob unscrews, then the little chrome bit behind it. LEAVE EVERYTHING CONNECTED. Once the switch is dangling below the dash, clean the wires off until you can see what color everything is, and take a couple of photos. Draw some diagrams. Mark the wires.

Then, pull all the wires off and apply some black tape to the spade terminals.

Start the car (should work fine), and verify that the ignition is operating normally. If so, you've isolated the problem to the switch. If not, then the ignition problem is elsewhere.

Note that new headlight switches are quite expensive. If you want to tackle at least a partial rewire, you can get VW switches for a Type 1 or Type 3 from Bug places for far less money, but they'll only have 6 or 8 terminals on them, not the 10 the 914 switch has. Even the 6 terminal switch should do everything you need (parking lights, low beams, dimmer), but you'll need to work out how to wire it up. Both switches look and operate 99% like the 914 switch.

If the ignition problem isn't the headlight switch, then you have a short elsewhere. Look at the back of the fusebox for burnt or loose wiring. Look at the wiring coming out of the steering column, too. The other likely culprit is the steering column switch. The electrical portion of the switch is fairly cheap ($15), but you'll have to disassemble most of the column to get at it.

I suspect your headlight switch has melted internally and is shorting together several circuits. The red/white wires, for example, if shorted to the red (battery) wires, will power your ignition as they tie together with the ignition power wires at the fusebox.

[grasshopper]

i have a headlight switch you can have (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[scruz914]

I would pull the fuses for the lighting circuits before removing switches. Fuses 1-7 and 9 are all for lights.

1 - left high beam
2 - right high beam
3 - left low beam
4 - right low beam
5 - left park
6 - right park
7 - license
9 - stop, turn, backup

Pull the fuses one by one, do not put them back, and see if something changes.

The ignition circuit is not fused. A possible problem could be a short in the seat belt warning circuit. Ignition wire 15 is connected to it as well as the buzzers and warning light. The headlight switch is definitely suspect but you could have fried wires in both the light switch and ignition. Check to make sure the ignition wire at the coil did not ground due to a loose coil. A big bump with a loose coil can cause it to ground and fry a few things.

Pelican has wiring charts on their web site. They also have a nice write-up on repairing the headlight switch.

-Jeff

[Dave_Darling]

Were any lightbulbs replaced on the car shortly before this stuff started? I had similar (but not identical) symptoms when I replaced a dual-filament bulb with a single-filament one.

--DD

[lapuwali]

Actually, if you're going to pull fuses, pull fuse 8. If battery power on terminals 15 or 30 (red wires) on the headlight switch gets shorted to terminal 58 (red/white wire) on the headlight switch, you'll get power backwards through fuse 8 to the black wire that goes straight to the relay board, and thence to the coil + terminal.

The red/white wires power the gauge lights, so technically, fuse 8 is also a "lighting" fuse.

[gklinger]

Wow! Thanks for all the good replies! This gives me some ideas on where to start diagnosing this mess. I've gone over the wiring at the fuse block - cleaning up terminals and such with no luck. There was one wire going to the left front marker light that had been fried sometime in the distant past that I replaced, but other than that everything looked fine. These symptoms did not appear before or right after that though, just out of the blue much later. I'll start diggin in to it tomorrow and keep you updated...

[94teener]

Garry,

Brake warning light: There is a wire connected to the brake master cylinder which will short out, turning on your brake warning light whenever there is a significant differential pressure between the front and rear brake fluid pressures. This differential pressures represents a potential failure of the either the front or rear brakes, usually due to a leak of fluid. Applying and releasing the brakes likely cause light to go out and on. The flashing brake warning light with the turn signals is due to the same master cylinder switch being activated (grounded).

The instrument lights may be on all the time because the reohstat on the back of the light switch is defecttive or you don't have it adjusted. The license plate lights are on the same circuit. It could be that the light switch is miswired. Pin 58b of the light switch should have a BK/BL wire attache to it.

Regarding the ignition remaining on when the switch is turned off, there is miswiring
for sure. Check to make sure that you have THREE WIRES, ALL BLACK on one end of fuse S9 and that you have THREE WIRES, TWO RD/WH AND ONE BK/WH on the other
end of S9. Let me know what you find.

Phil

[gklinger]

Holy CRAP!

Well, it seems that I have some melted wires... Both wires to terminal 58a and the wire to terminal 58b have lost their smoke. This is DAPO work for sure - standard electrical tape, and the liquid variety spread around to try to reinsulate this mess has obviously failed. These circuits appear to be for the instrument lights and 58b routes back to fuse 7 which also powers the license plate lamps. Looks like I've got some work to do.

One tidbit - I tried removing fuses one by one. None had any effect except fuse 9. Pulling that got rid of the symptoms reported before, including engine running with the ignition off and lights on.

Phil - all wires appear to be connected normally at fuse 9. Do you think the shorted wires from the switch could be the entire problem? Or should I be looking elsewhere also?

[94teener]

My advice is to re-wire as necessary back to the factory configuration, all the time ensuring that each wire goes where the diagram indicates. Keep the new/repaired wires separated loosely.
When reappling power, do it in a few seconds bursts, all the time eyeballing the wiring for
smoke. If there is no smoke and everything works, hey, your in fat city. Then you can tie up the bundles neatly. I will be in to inspect later.

Good luck at it,

Phil

[94teener]

Let me know if you need a replacement light switch, I'll send you one.

Phil

[r_towle]

Chase each circuit back to ensure you have no chafing somewhere else.

The wiring harness is held to the body by very very sharp pieces of metal that are folded over the wires...

these metal pieces are supposed to have a rubber cover, but some of them dont (ask me how I know)

It is a pain, but follow them the the headlights...there are about 10-15 of these metal pieces in the front trunk, three or four under the gas tank, drivers side that hold the harness to the body.

If the PO removed some of these rubber covers, you could be shorting out there (I was) and it is hard to tell until you take the wiring loom out of the metal piece and examine it...

It is after all 30 years old...

Rich