Negative Switching Headlights?

Here is the original wiring Diagram
Attachment 64814

Attachment 64815

Here is the original diagram

Yeah it's to do with the negative switching. You will need to change it to the second option I was talking about previously.

Disconnect the wire you connected to the black and white wire at the headlight plug and connect it to the black wire at the headlight plug (or the red wire if connecting to the LHS headlight).

Disconnect the earth wire at terminal 86 at the relay. Run a new wire from terminal 86 of the relay and connect it to the red and yellow wire at the back of the headlight plug.

The rest of the wiring is the same.

No worries mate i will try that and see what happens.
I believe negative switching was to prevent you from loosing both headlights if you get a problem with the system....i wonder if it is worth the trouble. lol

Your a Bloody legend Yendor, that did the trick and no surprises this time
Thanks for the help i would have been stuffed without it.....i think it's time to avoid Toyota wiring for a while
Cheers mate

Mojo

Negative switching is just another way of doing it. Instead of putting the switch in the positive side of the circuit the switch is fitted in the negative side. It just most people can understand what's happening better when it's positively switch.

All headlight circuits on all vehicles are set up so if a problem occurs the worst that should happen is you lose headlights on one side of the vehicle only. This is regardless of negative switching or positive switching.

Toyota have changed their headlight circuit over the years. They use to put a relay in the power supply going to the headlights. This relay would switch power off to the headlights when the lights were turned off. This relay now being missing is why you had the problem with being able to turn the spotlights on with the headlights off.

Can I ask where you got the wiring diagram from? Did you download it? I would like to get a copy if possible.

I must be one of the slow learners as well as it had me stuffed, but thanks for the help i needed it.
Check your PM
Mojo

Thanks for the PM it worked a treat.

Good stuff mate i am glad to be able to help someone else for a change

Hi, sorry to jump in so long after the party;)

, but I need help with a Toyota Corolla 2009 and a Whelen UHF2150A and you seem to know a little about Corolla.

I contacted Whelen to buy a UHF2150A, which is a wig wag for the headlights, but they told me it wouldn't work on my Corolla 2009.

The reason was that the lights were controlled by the computer and if you inserted this UHF2150A, it would give all kinds of error codes and just explode, at least, that's the impression he gave.

Is this at all correct and if so, why? Are there alternatives?