'79 Headlights Not Working

[trep01]

Headlights are not working. Running lights are. I checked the fuses designated to the low and high beams and the fuse block is getting no power for these circuits. When I jump these circuits the lights come on. I've been studying wiring diagrams for two days and cannot figure out the issue. Could it be the low beam relay? Where does the power come from that runs into the fuse block for these circuits? Could it be the switch even though the running lights and dash dimmer work? Any help would be appreciated. Thank you.

[busdaddy]

You have the ignition switch on, right?
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[trep01]

Indeed I do. Also, now my backup lights aren't working, either.

[busdaddy]

Power comes from the ignition switch to terminal X n the headlight switch, it stops by the fuse box but isn't fused, but there is a connection on the bus bar. From the headlight switch's terminal #56 it goes to the relay and then on to the individual headlight fuses.
Check for power at 56 on the relay and then work back up the chain, headlight circuitry depicted around current track 16 here: https://www.thesamba.com/vw/archives/info/wiring/76-79113wiring.jpg

X also powers the wipers, do they work?
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[sjbartnik]

OK so the power for the headlights does not come from the same source as that for the running lights. Running lights are powered by a hot wire (30) to the headlight switch which gives them power all the time.

Headlight power comes to the switch from the X circuit. The X circuit into the headlight switch only gets power when the ignition switch is turned on.

So, you get your voltmeter on the back of the headlight switch, you turn the ignition on and you measure for 12v at X terminal. If you don't have it, you trace back to the ignition switch.

If you do have it then you turn the switch on and check for 12V on the 56 terminal (white/black wire). That sends power to the hi/lo beam relay. If you have 12v out on 56, switch is good. If not, switch is bad.

If you have 12v into the relay on 56 but no 12v out on either 56a (high beam, white wire) or 56b (low beam, yellow wire), then relay is bad.

Backup lights not working is completely unrelated. Backup lights are powered by a connector on terminal 15 of the ignition coil. Power goes from coil through an inline fuse to the switch on the transmission, then from the other side of the switch to the lights. Check for blown or corroded fuse. If fuse blows again after replacement, you have a short somewhere in that simple circuit, so trace it out.

EDIT: Backup lights *could* possibly be related if in fact the ignition switch is bad and is not putting 12v out on X and 15 when switched on. But in that case the car would not run. Does it run?
_________________
1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[trep01]

Thanks for the replies. Car runs and the wipers work. I checked the in-line on running to the coil and the fuse was good. I cleaned the inline housing connections to make sure there was a good connection and the backup lights still don't wonk. Also noticed that the license plate light is also out now. The gremlins are attaching from every direction. I'll remove the headlight switch and run the test. Thanks again....

[trep01]

I have 12 volt at the switch when the key in turned on. Looking at the Bently manual I can't really tell where the relay is. I know it's on the back of the fuse bank, but what reley is it?

[sjbartnik]

For the backup lights, next step would be to test the switch. It's a simple open/close switch. With the trans in any gear except reverse and the key on, you should have 12v at one of the terminals on the switch (the one connected to terminal 15 on the coil). When you put the trans in reverse, that closes the switch and then you should see 12v out on the other terminal. If not, switch is bad.

If so, problem is elsewhere. I believe the wire runs from the switch to a splitter connector somewhere in the engine compartment, perhaps behind the tar paper on the firewall, that sends the 12v to each backup light. I believe there are other connections in that connector for taillights etc so that may be a place to look for your license light issue too. The license light is powered off of one of the taillights.

Of course for the license light it could just be that the bulb is burned out.

Same could be true for the backup lights but unlikely for both to burn out at the same time.
_________________
1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[sjbartnik]

[busdaddy]

There's only 3, one is a little 1" cube, that's the key buzzer, the signal flasher is usually 1" x 1" x 2" and black, the headlight relay is usually 1.5" x 1.5" and silver.

_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[ashman40]

[vwoldbug]

Follow these guys and please let us know . Good luck

[trep01]

Thank you for the responses. I'll take this into consideration as I continue to chase this issue down. I appreciate your time and will post my progress.

[ashman40]

Here is a simplified headlight circuit diagram from Speedy Jim’s site:

_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[trep01]

Thanks for the wiring diagram. I traced it all down to a bad relay. I swapped out for a new one and now have headlights. However, the high-beams are not working. Back to the multi-tester.

[busdaddy]

If the new relay has a #30 terminal you'll have to jump it to #56, or power it from a red circuit on the fuse box. Most originals on USA cars don't have that terminal and the one style for the whole world replacements do, it won't change beams without it powered.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[trep01]

That is exactly the issue. Thank you