So I searched and read through this thread:

http://www.914world.com/bbs2/index.php?sho...eadlight++relay

But it didn't quite cover what I was looking for. But I did notice a couple of people asking if the car was a '73. Mine is a '73. But I didn't see anyone say why that mattered. Is there something specific about the '73 model that has headlight issues?

Anyway, here's my issue: With the battery connected and the ignition switch on, when I pull out the headlight switch, both lights flip up but neither lights up.

A little history: This is the same car that you all have been helping me get started in this thread:

http://www.914world.com/bbs2/index.php?sho...eadlight++relay

Part of the problem this community helped me figure out was that my ignition switch was broken. So I replaced it with a new one. So I have a new, working ignition switch.

I thought that maybe the high beam/low beam relay had gone bad, so I bought a new one from Automobile Atlanta. Like you can see in the pic, it has five posts, and the description says that it fits 70-76 914. However, when I removed the old one from the car, it only had four posts and four wires connected. So I connected the wires to the corresponding posts on the new relay and left the fifth post empty.

Click to view attachment
Click to view attachment

After installing the relay, I still had the same problem: The lights flip up, but won't turn on.

Another monkey wrench: my turn signal stalk is broken. The internal mechanism flops around all over the place and the turn signal swings loosely. I know that the turn signal stalk is also the high beam/low beam switch so I'm wondering if that could cause the lights to not turn on.

What are your thoughts?

porsche changed the design, the new ones have five terminals, so you have one of the old original four terminal ones. Simply jump from the 12 oclock position to the 9 oclock position and it will work perfectly. If the headlights do not turn on at all on any beam, you may have a bad headlight switch Click to view attachment


Click to view attachment

OMG! It's $300 for a headlight switch!

Are they repairable or does it have to be replaced if bad?

one thing at a time....

Ok, so things just got interesting...

I jumped the two terminals like what was described in that photo.

Click to view attachment

And as I looked at the pic, I realized the wires were not correctly attached. Yellow was going into 56b and white with blue was going into 56a. So I put them the way the diagram said.

I connected the battery, turned on the ignition, and pulled the headlight switch. Both lights lifted up but neither turned on. However, when I pulled the high beam lever, this time both headlights lit up. I checked the fuses and with the high beams on, both fuse terminals 1 and 2 gave me a test light. But with high beams off, I get no test light on fuse terminals 1 thru 4, on either side of the post.

So no power from switch/relay to low beams. But I do get power from switch/relay to high beams.

I hope that means I don't need a new switch.

Is the engine running?

No, I have not ran these test with the engine running, just the ignition key in the ON position. Does that make a difference?

On my 71, which may have different wiring, unless the engine is running the headlights will not illuminate.

I started the car last night and even with the engine running, the low beams would not come on, but the high beams still do.

Hmmm. If no power to fuse panel on low beam, and your relay is good (try swapping with another known good relay?) the you may need a new fuse panel. This is just my WAG So please don’t spend more $ until a real expert chimes in.

Are you 100% sure the bulbs are good?

I have not checked the bulbs, but with both of them responding the same way and with both fuses not lighting up, a assumed it must be something before the bulb. Unless a bad bulb can cause the fuse not to light.

Bulbs are always replaced in pairs!
The reason is when one goes, the other gets more current and is bound to go due to that fact or due to the fact is is as old as the other one and just nearing end of life.
So in short, the chances both lightbulbs are gone is very real!

I have a 76 and am experiencing a similar problem. Interested in the outcome but also wanted to let you know that my lights were working and then stopped when I was using the turn signal arm to go from low beam to high beams. Don't drive at night so I didn't investigate right away. Drove the car a few weeks later and decided to try the lights again. They worked!! Low beams then went to high beams. Worked.

Then I tried to go back and forth from low to high and they went out and stopped working again. Sounds like its in the steering column for my problem.

Considering you just replaced the ignition, maybe your issue is in the column as well?

I had similar happen to my '75 914, I ended up having to replace the high/low relay.

Try pulling down the fuse panel and use the test light directly on the high/low relay itself.

With the key switch in the on position, and the headlight switch turned on, you should have power all the time on terminal 56 (thick red wire with white stripe) and 30 (which should be jumpered together, as you mentioned) that's the single power feed coming from the headlight switch.

With the low beams on, you should have power at terminal 56b (thick yellow wire), and your test light should turn on when touching that terminal.

With the high beams on, you should have power at terminal 56a (thick white wire), and your test light should turn on when touching that terminal.

Terminal S (thin yellow and red striped wire) is the wire that goes up to the steering column switch.

So knowing that the test should be:
Ignition switch to On
Headlight switch On
High/Low Dimmer set to Low

When you have that configuration, use the test light to probe 56, and 56b.

If your test light DOES turn on when you probe terminals 56 and 56b, but DOESN'T turn on when you probe fuses 3 and 4, then the relay itself is fine, and you need to check the yellow wire between those two points.

If your test light DOES turn on when probing terminal 56, but DOESN'T turn on when probing 56b, then your high-low relay is bad.

One thing you can try is to wiggle the 56b terminal and see if that's enough to make contact, I noticed on my replacement hi/low beam relay, the base where the terminals go through was flexible enough that if I pushed on the terminals around, the internals of the relay were able to move and affect the movement of the relay contacts, preventing it from working.

It seems unlikely that the headlight switch itself is bad since your high beams are working, both of them receive power from the same spot on the headlight switch, the dimmer relay just directs it between the 2 filaments. So if the headlight switch were bad, I'd expect both of them to not work.

A test light is a good first step. You should use a digital multimeter and measure voltages. If you don't have one, they can be purchased at any FLAPS, Home Depot, Lowes, HF.

Looking at the schematic of the '74 914 below, if your headlights work on high beams, then the headlight switch is ok. There's only one wire from the headlight switch to the hi/lo beam relay. You should measure voltage at the relay on pin 56a since that is where the low beam voltage comes from. One could say that you can measure the same voltage at fuses S3 and S4, that could be the first measurement.

You know the low beams do not light up. You have measured voltage at fuses S3 and S4 (Both sides I hope). If no voltage at S3 and S4, measure voltage at the relay at pin 56a. You know there's voltage at pin 56 since the high beams work.

@Spoke well summed up. I also got my 56a and 56b terminals reversed in my troubleshooting steps, I was going off this pinout description which is opposite to the description in George's post.