H4 Headlight Bulb Wiring

[PJ57]

Hey all, As per a previous post, I currently have type R lights on the chim, and the main beam is shocking bad.



On examination, it looks like the main beam bulbs are coming on at dipped level.

I have the bulb wiring below, and I am assuming that there is only one wire going to the bulb from the main beam relay.


Does any one know if the dipped beam terminal on the bulb stays live when the main beam comes on? Or do I just need to run a positive to the main beam terminal and leave the dipped beam bare. (As the dipped is running off a different bulb and lens with this setup).

If both elements need to run at the same time (dipped and main), if I bridge the terminals, will the single wire from the relay to the bulb take the load?

Thanks

[ukdj]

If the wiring is the original TVR loom then I wouldn't advise bridging the two, the original grade of wire was shockingly under spec, to the point where you got almost as much light out of the glowing wire as you did the bulb!

[mk1fan]

Someone's done a poor job on the conversion there. Those units should have H7 bulbs.

[PJ57]

Thanks guys.

That would explain it. Is there a difference regarding dipped and main beam on the H7's as I see they only have 2 terminals so presumably main will be just as bright as dipped?

Thanks

[Pink_Floyd]

PJ57 said:

Is there a difference regarding dipped and main beam on the H7's as I see they only have 2 terminals

H7 bulbs don't have the concept of Main or dipped, they are just a bulb, the housing that you put them into shapes the beam so that it becomes a Main or dipped pattern on the road.
I can well imagin that a H4 bulb in these lights would give a pretty poor beam pattern.

[PJ57]

yep, think that's the problem.

Thanks for you help