Problem with high and low beams

[Habba]

Hello everyone. I'm restoring an European spec 1970 Beetle back on the road. Its been sitting under a tree for +20 years in Finland, and I'm getting close to bring her to the MOT.

This problem with headlights is still bugging and I would really appreciate help. I have a new headlight relay installed, I rewired the front lights to a some degree, and I have new H4 bulbs. All the lights are working as they should, but the problem is, that when I'm switching from low to high beam or vice versa, the relay gets stuck. Sometimes it gets stuck after the first try, and sometimes it can take two or three trys. When I shut the lights and let it be for a while, the relay again works but then seizes after switching from low to high or vice versa.

I have confirmed that the relay is OK, and the stalk coming from steering colum is OK. The relay behaves the same way even if I ground it directly through the S pole on the relay.

I would really appreciate help, I have no ideas where to go next. Thank you.

J-P

[minirailz]

The relay should stick when the lights are on.
In this case it is used to switch between high and low beam.

It should not stick when lights are off.
In this case it is used as a high beam flash only.

From what you said, I think you isolated the problem to the relay.
Have you tried a new relay?

Dennis

[Habba]

Hello Dennis,

Thanks for your reply. I have a new relay installed as I thought originally that is was the probelm, but it didnt make any difference. The behaviour is the same with the old and head headlight relay.

And to clarify the situation: The relay behaves the same if the headlight switch is on or off. If the headlight switch is OFF, pulling the stalk will flash the high beams, but only for maybe once or twice, and then the relay makes an abnormal noise and the high beams wont flash again when you are pulling the stalk once more.

If the headlight switch is ON, the low or high beams are working normally, and when you pull the stalk (or ground the relay manually), the lights will switch maybe once or twice, and then the relay makes the same abnormal click when trying to change, and the lights are stuck on one of the two positions.

Then after a while, the procedure mentioned above can be done again.

So the relay works just like it should for a couple of times, and after that, it stops working. This is the weird thing!

[minirailz]

Are you able to measure the voltage on the relay?
Just to see if it has a bad ground for example?

Did the old relay behaved the same?

Dennis

[Habba]

Hello Dennis,

Yes, both old and new relays behave the same. Here are the voltages you requested:

Light switch in cabin ON, voltages on relay poles:

30 = 11,75V
56 = 11,6V
56a = 0,19V
56b = 11,52V
S = 11,7V

Light switch in cabin OFF, voltages on relay poles:

30 = 11,96V
56 = 0
56a = 0
56b = 0
S = 11,98V

Why the relay is not changing the beams even if I ground the S pole manually?

[Starbucket]

The H4s are drawing too many amps overheating the relay get one with a higher amp rating like a horn relay.

[Habba]

[Habba]

Update to the situation: its looking like Starbucket was on the right track. I disconnected 56a and 56b from the relay and tried it. Now its working (clicks every time I pull the stalk without getting jammed).

Now the question is, why the relay is not able to handle the H4's, even though the spec says it can handle 150W of load...

[minirailz]

Good news!!
Thanks for sharing.

Just as a reference, the original bulbs are 40/45w bulbs

Dennis

[Habba]

Hi Dennis,

Yes, thank you and Starbucket for your support!

But I have fresh news from the garage: It wasn't the H4 bulbs that were the culprate, but rather some contact issue . I'm not sure what was the problem, but I went throught all of them at the terminals in the front compartment, and now the lights are working as they should!

So long story short: Always check and clean the connections first...