Had a look at the connector block that plugs onto the back of the main beam H7 bulb (mine are factory xenons).

There is one yellow cable & one brown cable. I need to know which is positive & which is negative.

Any help would be greatly appreciated.

Cheers,

Jon

Lummox??

Jon,

Brown is earth (same colour as soil!).

Jon,

Brown is earth (same colour as soil!).

Very funny mate!!

Wasn't entirely sure, as the yellow cable through me!

I thought so :-)

You still going to fit that HID kit then?

Might be!

Good luck with it. Should make a nice set of very white lights on the front of you car.

I'm still trying to sell my car, so no more mods for me!!

Just think though, nice Porka lined up if you do sell.

Yorkshire man in my head says £100 lost if I don't!

Yorkshire man in my head says

To find out which is positive ,use a 12 volt bulb (anything from 3 to 6 watts) on 2 leads .

1.Turn on Lights

2.Connect one lead to a good ground connection (chassis).

3.Connect the other lead to one of the wires you want to find positive (battery + sign)

4. If the lamp lights ,that wire is positive

5.If the lamp does not light ,that wire is negative (chassive)

This method can be used to find a positive anywhere on the car. ie to check whether a fuse is blown

This method is better to use than a digital (or analogue) meter , because the lamp method draws current ( 6 watt bulb takes 1/2 amp to light ) , A meter draws (takes current) ,but a very small amount. It is possible to get a voltage reading ,when the wire being tested is not connected to + 12 volts,but lays next to another wire that has a voltage on it .

Had a look at the connector block that plugs onto the back of the main beam H7 bulb (mine are factory xenons).

There is one yellow cable & one brown cable. I need to know which is positive & which is negative.

Any help would be greatly appreciated.

Cheers,

Jon

You might end up in hospital If you did that with Xenons Andy!! They run at something like 25000 Volts!!!!! There's big yellow warnings all over after market kits (i had one on my old car). Dont think a 12v bulb would like it much either!!!

I'm just checking the polarity on the OEM main beam connector block which is normal H7.

I'm not even gonna think about touching the ballast wiring!!

thanks TommyC ,I take your point.

I was answering the query about 'How do I find which wire is positive(12 volt +) supply.

Perhaps I should have included -'Connect leads and then ,turn on'

If you connected a 12 volt bulb across the high voltage (25,000 volts) supply ,

you could blow up the high voltage module. When a 12 volt lamp test lamp is connected you would not get 25,000 volts you could touch ,because such a low resistance of the 12 volt bulb would short out,the high voltage to nothing. The module is not built to supply 25,000 volts at 1/2 amp, which is 12,500 watts!!!. If it was to produce this it would be huge. I am 'Old School' and do'nt have high voltage headlamps. If you are incompetent ,in electrical matters ,get somebody qualified to do the work. Bearing in mind the majority of a car runs off a 12 volt battery , which is not dangerous.

thanks TommyC ,I take your point.

I was answering the query about 'How do I find which wire is positive(12 volt +) supply.

Perhaps I should have included -'Connect leads and then ,turn on'

If you connected a 12 volt bulb across the high voltage (25,000 volts) supply ,

you could blow up the high voltage module. When a 12 volt lamp test lamp is connected you would not get 25,000 volts you could touch ,because such a low resistance of the 12 volt bulb would short out,the high voltage to nothing. The module is not built to supply 25,000 volts at 1/2 amp, which is 12,500 watts!!!. If it was to produce this it would be huge. I am 'Old School' and do'nt have high voltage headlamps. If you are incompetent ,in electrical matters ,get somebody qualified to do the work. Bearing in mind the majority of a car runs off a 12 volt battery , which is not dangerous.

D'oh!! Yeah, i should've realised it'd blow the module (i'm studying DC and AC theory for HNC engineering at the moment) just didn't think too much into it. I get scared about electricity when the numbers get that big though!! Have this in-built reaction of "DON'T MESS WITH IT" when i do see warnings like that (i triple checked all the connections on my old car before turning them on for the first time!!).

I have "old school" lights on my fabia. I only fitted Xenons to my old car because the standard ones were cr*p.