Headlight not working properly?

CHRIS4242

MEMBER
2010 FORD FALCON
4.0L
6 CYL
4WD
AUTOMATIC
84,000 MILES

Hi,

My car's headlights stop working whenever I turn the A/C in cool mode. But these lights work when I turn on the A/C in heat mode for few minutes (5 minutes). Not sure what's causing this issue. High beam and signal lights work fine.

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,328 POSTS

Hi,

This model isn't offered in the US, but I will try my best to help.

Based on your description, to me, it sounds like there is a common ground being used by the affected components. If the ground is weak, it may work fine with one or the other turned on but fail if both place a load on it at the same time. Also, a circuit breaker can act this way if it is failing.

By chance, do you have a repair manual for the vehicle? If you do, does it include a power and ground distribution schematic?

Let me know. Normally, I have what I need as far as schematics. Because this is not in the US, they aren't provided in my manuals. I tried finding something online as a reference, but everything I'm finding is for the US-made Ford Falcon from the 1960s.

Take care and let me know if I can help in any way.

Joe