Help. Headlamps Wiring Problem

[aronw2004 4 1 Cars]

Hi. Iv put everything back after a restoration project and now the headlamps are wrong. When im on dip, the lamp is on full beam and vice versa. Iv obvioursly connected something the wrong way. Any ideas?

[jackherer 543]

Did you use all the original looms and fusebox etc or is any of it from other cars?

 

I'm struggling to come up with ideas for what you might have done as all the connectors are keyed so there should be no way to mix anything up like this.

 

It might be an earth issue, the front panel ones and the one on the steering column bracket or possibly even the rear one behind the passenger light.

 

Do you have everything connected including driving lights? If the driving lights aren't connected are their wires secure and not shorted out or anything?

[dobboy 231 2 Cars]

Doubt it will be an earthing issue, you could measure resistance from the earth pin of the lamp holder plug to the neg battery terminal to make sure. It should be very low resistance I.e less than 1ohm

 

Not messed about with lights on mines but is there a relay for full beam? If so I'd check you have plugged in the correct relay into the correct socket It sounds like a what should be a N/O contact on a relay is operating N/C.

[aronw2004 4 1 Cars]

Think iv found the problem. I had a spare lamp here and the imagery was fine through that one. The difference between the two is the rotation of the bulb holder. Mine had two arms at the top and the other lamp had one on the top so it must be that the bulbs were in a way upside down. Lol

[jackherer 543]

I agree it was unlikely to be an earth issue but I wouldn't have ruled it totally out, the only relay is for the driving lights but it does behave very oddly when the headlights are disconnected.

 

So are you saying it wasn't actually swapping dipped and main, it was just the upside down bulb making it appear that way?

[aronw2004 4 1 Cars]

It must have been the upside down bulb that made it seam that way. Failed the mot on that. These garages seem to do less and less work for an mot these days. The rear fog lamp had a bad connection also. All it needed was a little twist but he didn't touch it. Iv had one in the past failing an mot because of a poor wiper blade. I then asked if he had ran out of them. He said no I wasn't sure if you wanted me to change it.!!!!! WTF no id rather it ffailed.