Low beam only working when high beam turned on???

[Kurt141]

This is doing my head in!
Got in wife's car other day (vz acclaim). No low beam! High and Parkers work though.
Bit more investigating and found the low beams come on when I turn on the high beam, but otherwise they won't work.
Done a search on here and found several threads about low beams not working at all but nothing like what I've got.
Any ideas anyone?
I've checked all the obvious stuff, relays, fuses etc. but I'm lost! Just hoping it's not something in a bcm or something.
For now I'm going to remove high beam globes so she can drive if needed at night (she only drives in town anyway and never uses the high beam). Want to sort it out though!
Cheers

 

[mpower]

I'd be willing to bet its the switch.

Get an auto-electrician to confirm it.

 

[sidecar55]

Combination switch.

 

[axemurderer101]

Low beam relay is my guess.
Your low beam wont be coming on with your highbeam, the h4 lowbeam globe has 2 filaments so when you flick to highbeam the second filament lights up.
Try swapping your high and low relays around.

 

[Kurt141]

Aren't the high and low beam relays different types (ie. not interchangeable)? I swapped the high beam relay with fan relay and low beam with horn and no change.
Judging by my owners manual the high beam is the larger square grey coloured type relay and the low beam is the smaller rectangle black relay? Am I right?
If what your saying about the h4 globe having 2 low beam filaments, that makes some sense as to why when you flick the stalk to high beam the low lights up too. Thought it was strange considering the combo switch and stalk are no where near each other!

 

[Silverbird]

This is doing my head in!
Got in wife's car other day (vz acclaim). No low beam! High and Parkers work though.
Bit more investigating and found the low beams come on when I turn on the high beam, but otherwise they won't work.
Done a search on here and found several threads about low beams not working at all but nothing like what I've got.
Any ideas anyone?
I've checked all the obvious stuff, relays, fuses etc. but I'm lost! Just hoping it's not something in a bcm or something.
For now I'm going to remove high beam globes so she can drive if needed at night (she only drives in town anyway and never uses the high beam). Want to sort it out though!
Cheers

Certainly could be relays as suggested, bear in mind also that failed filaments in these bulbs don't always look broken to the naked eye. Try new bulbs if swapping the relays doesn't work.

 

[XUV]

Have a look on top of your lights, with the bonnet open, it should have what globes it take ie Low Beam H? High beam H?

If it's an H4 , they do have two filaments High/Low , and Low beam could be shot, two at once, hmmm , more likely a relay.

It's the first bit of writing on top.

 

[hakhawk]

you say youve checked all the obvious stuff, but i dont see "checked the globes themselves"?

 

[Kurt141]

Considering I have low beam when on high beam, I didn't really think they could be blown? However as mentioned if they are H4 globes and have dual filaments it's worth a look. However, as mentioned, both blown at once....... Unlikely.
I'll take a look later today.
Cheers

 

[hakhawk]

h4 is a high beam and low beam, it might look like low beam is on, but its most likely the high beam filament.

when was the last time you drove it at night?

its amazing how many people drive with just one low beam light without realising, then when the second one goes they just assume both have gone at the same time