I was wondering if any of you guys have ever seen this.

I've got the wiring diagram pulled up trying to trace down what I believe to be a bad connection somewhere.

I installed new H4 bulbs awhile back. They worked fine for months. I can't remember if I had this same issue with the 40/45 watt incandescent bulbs or not.

The problem is, the RH side main beam sometimes works and sometimes it doesn't.

The weird thing is when this particular light is not working, the green indicator lamp in the steering column also doesn't work.

I'm trying to make heads and tails of the diagram enclosed. it's showing two relays and a resistor in the circuit.

See attached wiring diagram.

This diagram maybe the UK version that turns the dipped beams on at a lower intensity when the park lights are on you guys were talking about in another thread. My car is French spec so it shouldn't have this setup.

I'm assuming the green wires are dipped beams and the yellow wires are the main beams. Then the yellow main beams split off into brown wires going to each headlight. That seems confusing considering the earth wires are also brown.

Since the wires going to the main beams split downstream of the green dash indicator, this baffles me as to why the indicator doesn't work when the RH main headlamp is not working.

I don't think it's the switch, otherwise neither main beam would work. I don't think it's an earth, otherwise the dipped beam and park light wouldn't work in that headlamp.

It's possible it's the bulb. I could swap bulbs from side to side to see if the problem crops up on the left hand side.

I replaced the connectors at the bulb. They seem like they are making good connection.

The problem is somewhat random. Next time this bulb is not working, I'll check for power just to make sure then work my way back.

Just curious if any of you guys have ever seen this before.

Most would suggest to remove the dim dip resistor set up.

ps
Citroen wiring!
You have probably spotted it, but Citroen use coloured sleeves to identify wires
See

Yeah mine is lacking that resistor setup.

I was aware of the colored sleeves but didn't think the headlamps were fused protected. What's supposed to prevent the wiring from shorting out?

The picture is just show the sleeves, standard 2cv has no fuses in Headlamps.
I put fuses in for a lot of circuits and relays in to save the switches, used these, small and water proof.

There is a splice in the loom. The main-beam wire from the switch goes to the left-hand headlamp. Somewhere* inside the main loom, crimped to that wire, another wire is added and goes to the right-hand headlamp. That wire then has another crimped to it for the main-beam warning lamp on the dash. *From memory, I think that first splice is in the part of the loom that runs past the battery/starter/air-filter, but I'm not certain about that. If that splice has got corroded or loose, it could be causing your fault.

I will check it out. Any reason why the indicator and the headlamp stop working together when this happens?

I've found all sorts of bad connections on this car and new ones seem to crop up all the time. Which is to be expected with old cars.

Yes:
If the connection at that splice separates, it just leaves power to the left-hand headlamp, along the first wire. The second wire, from that splice, takes the power to the right-hand headlamp and then the warning light.

I think you are on to something.

Before this started, I noticed that the RH main headlamp was slightly dimmer than the LH main beam. Not real noticeable while driving but while standing in front of the car. But the intensity of dipped beams seemed the same.

Initially I thought it may have been mismatched bulbs or my mismatched headlamps. One is made by Cibie and the other one is made by Marshal. Interesting, one of these has a tab that can be moved to make it either legal for LHD or RHD.

Then after I installed the H4s I got from you, I still had the same issue.

So I figured it was a poor connection caused by corrosion somewhere. I just never bothered to trace down where the main beam wires connect.

I'm going to pull all of that loom the PO installed in the engine compartment and trace these wires down and see what I can find.

Check also all the connectors that are tyed up to the headlamp bar. They can corrode easily if the rubber flap isn't wrapped. Take a very thin round file and clean inside of the female connectors the male can be cleaned with fine sand paper. Also the rubber bushes around the female connectors must be in good shape. Cracked ones don't provide enough pression to make good contact.

I've had to take a pair of those spark plug wire crimpers and squeeze the female connectors in a bit to make a better connection. Particularly the ones the connect to the park lamps in the headlights.

These type sold at automotive stores don't seem to fit all that snug.



These type look like they would fit better: