Headlight question !!Help!!

[bmdublu]

I have an 87 E30 325 and the problem I am having is in the headlights. Both my low beams come on but when I put my high beams on only one low beam stays on and the other one turns off. I can't pass inspection like this. Does anyone have any experience with this? I've changed out the light and still get the same results. Is there a relay somewhere? Any help would be appreciated.

[bertible]

The Low beam lightbulb on 4 light systems is actually a Low/high beam light with two filaments in different spots inside the bulb to cast light on different parts of the reflector or internal shield. The three wires in the connector consist of a low, high, and ground, so you can easily check whether the power is getting to the right connector with a test light or multimeter.

When you speak of the "low" that goes out when you flick to high, the first thought is that it might have a bad high beam filament or connection, but the low is okay, since it comes on. Since you said you've changed the light, it can't be the filament, but might be the connector or wire to the high beam filament. At the age of our cars, the connector and wires can be fried, fretted, or simply bent too wide to make a good connection. I've done this (melted the connector) by running 80/100 watt H4 bulbs (now switched to lower) To solve it, I'd try fiddling with the connector while the high beams are on to see if the light comes on. If so, you've found the problem and need to tighten it up or replace the wiring. Otherwise, I assume you've looked at the fuses. I don't think the low and high are separately fused, but I always check fuses as the simplest fix.

Good luck.

[bmdublu]

Thanks for the help. It came down to a couple different broken wires that corroded through right at the connector. A little solder and a gentle hand and I'm all set again.