Headlights not working

[Seafrigate]

My running lights work but not headlights,put new fuses in , new headlight switch and new headlight lamps ,still no go.where are the grounds located so I can check them.1977 124

[zachmac]

Metal circles with multiple connections points (like a spider) attached to either inner fender towards the front of the car up top under the hood. Also one under the dash next to the ignition switch. BUT, I am pretty sure the headlights ground locally at the buckets, not back at the ground pods.

The wiring diagrams for your car are here: http://fiat.artigue.com/wp-content/uplo ... ider_C.pdf

With the ignition switch on power is sent to the light switch and the high/low beam part of the steering column multi-switch. This is the light blue wire to 46, the light switch and brown wire from 46 to 42/1, the steering column high / low beam selector on diagram. Check one is that you have power to those two spots with the ignition on.

When the lighting switch is put in the headlights on position it connects the incoming feed to the green output to the hi / low selector. If low beams are selected the 42/1 switch send power to fuses 5 and 6 sending power to the gray with black driver's side wire and gray passenger side wire going to the low beam headlight connection. If high beam is selected the 42/1 selector sends power to the 3 and 4 fuses and sends power via the green / black wire and green wire off those fuses to the high beam connectors on the driver's side and passenger's side, respectively.

Check for power with the ignition on, headlights on, and switch selected to low beams at the connectors under the hood on either fender near the front. gray/black on driver's side should have volts and gray on passenger side. Repeat check for volts on green/black and green wires with high beams selected.

Based on readings figure out where power is being interrupted.

[Seafrigate]

Thanks for the help.I bought this car when I got out of the service during Vietnam brand new ,have kept it ever since.always in garage and never in winter,now retired I enjoy working on it and keeping it immaculate.Years ago around 1979 I had a solid Koa wood dash made and it is still looking good

[spider2081]

It is kind of unusual to loose both the hi and lo beam headlights. Each bulb has a separate fuse for hi beams and then separate fuses for lo beams. 4 fuses total. Each light bucket has its own ground wire going to the grounding pod on its respective fender. The common wiring would be the wire that connects the "INT" terminal of the ignition switch to the headlight switch. However if this connection were bad your running lights would not work when the headlights are selected.
Is there a chance someone installed relays for the headlights on your car??? Or that your headlight wiring has been modified??

[davery]

It is kind of unusual to loose both the hi and lo beam headlights. Each bulb has a separate fuse for hi beams and then separate fuses for lo beams. 4 fuses total. Each light bucket has its own ground wire going to the grounding pod on its respective fender. The common wiring would be the wire that connects the "INT" terminal of the ignition switch to the headlight switch. However if this connection were bad your running lights would not work when the headlights are selected.
Is there a chance someone installed relays for the headlights on your car??? Or that your headlight wiring has been modified??

If a relay was installed would you install two, one for lo and one for hi? I know that is how the 83-85's are.

[zachmac]

In his original post in the new member section he mentions the running lights only work in the first light switch position, nothing works in the headlights on position. This makes sense as the running lights in position 1 run off an un-switched feed independent of the ignition switch. All of this points to either:

1) bad connection between ignition and lighting switch
2) bad connection between light switch and high /low beam switch
3) grounded wire somewhere in the feed circuit between the ignition switch and the headlights

#3 happens most commonly when wires in the column switch get frayed or broken. I have one right now I need to locate that grounds out everything and kills my ignition if I don't position the column switch just right. Need to add that to the to do list!

See if you have power from the ignition to the lighting switch. If no then that is the issue. If yes then check power from the brown wire on the light switch is getting to the column switch. If yes then check for power at the fuse box (fuse 5 and 6 for low beam, 3 and 4 for high beams) when the light switch is headlights on. It is VERY unlikely the issue is further out than this, unless there is a grounded hot wire in the head light supplies.

[zachmac]

I really easy and quick way to eliminate everything downstream of the fuse box is to jumper a hot 12v to the 3, 4, 5, and 6 fuse one at a time. Doing so should light up the left high beam, right high beam, left low beam, and right low beam, in that order. If that works you've quickly eliminated all the downstream wiring and can concentrate on the upstream feeds as described above.

[davery]

I really easy and quick way to eliminate everything downstream of the fuse box is to jumper a hot 12v to the 3, 4, 5, and 6 fuse one at a time. Doing so should light up the left high beam, right high beam, left low beam, and right low beam, in that order. If that works you've quickly eliminated all the downstream wiring and can concentrate on the upstream feeds as described above.

That is a really good idea. I am having issues with my lo beams and front markers and will have to try this.

[spider2081]

In his original post in the new member section he mentions the running lights only work in the first light switch position, nothing works in the headlights on position. This makes sense as the running lights in position 1 run off an un-switched feed independent of the ignition switch. All of this points to either:

Thanks I missed that post.
It would be nice to know if this car has an original Sepia ignition switch or if someone tried to install a Lada replacement switch and improperly connected the headlight wire. Also if the headlight wiring has been modified in some other way.

Looking at the wire diagram for a 1977 Spider it looks like the ignition switch has the push on terminals at the switch. The light/blue wire should be connected to the "INT" ignition switch terminal, if the ignition switch is the original Sipea brand switch.