Upgrading to halogen headlamps

[Crockett]

Hi,

I have some questions with regard to upgrading from conventional 45W + 40/45W headlamps  to halogen 60W + 55/60W headlamps, which I hope to get some opinions on.

I can understand that it would at least be important to install a relay so that the inner main beam lamps could be powered via this from the battery, rather than drawing power from the existing wiring, otherwise these would be drawing 240W (17.7A)  as opposed to the original 180W (13.3A) across the original wiring which I think might be intertesting!

This would then leave the two outer main beam lamps drawing 120W (8.8A) using the existing wiring, where the conventional lamps would have been drawing 180W (13.3A) for all four lamps, so theorectically this is okay.

I have three questions however.

1. Is it okay to be drawing 60W (4.4A) for each of the two remaining outer main beam lamps across the wiring that would have originally have been designed for 45W (3.3A)?

2. Is it okay to be drawing 55W (4A) for dip beam for each of the two outer lamps across the wiring that would have originally have been designed for 40W (2.9A)?

3. Assuming the answer to question 2 is yes, is it okay to be drawing 110W (8.1A) for the two dip beam lamps across the wiring that would have originally have been designed for 80W (5.9A)?

The alternative to the above would be to install two relays, one for dip and one for main beam, so that all the lamps draw the current from higher specification wiring and do not draw heavier loads from the existing wiring at all.

Any opinions would be welcome.

Regards
Daryl.

[DaveKent]

the standard wiring is more than capable of powering the halogen conversion.  most people think the wiring will melt when using the halogen lights, however it is usually the switch contacts which cause a problem. the increased current accros the contacts causes them to burn, so you need to keep that current as low as possible, hence the use of relays.

[Crockett]

[quote by=xyv link=Blah.pl?b=2000,m=1157618047,s=1 date=1157622399]the standard wiring is more than capable of powering the halogen conversion.  most people think the wiring will melt when using the halogen lights, however it is usually the switch contacts which cause a problem. the increased current accros the contacts causes them to burn, so you need to keep that current as low as possible, hence the use of relays.[/quote]

So based on this I figure I would be okay with the two halogen dip beams (2x 55W) across the switch, as it's designed to cope with four main beams (4x 45W) but I'd better not put four halogen main beams (4x 60W) across it. In which case I'll take the option I discussed to supply the two inside halogen main beams (2x 60W) lamps via a relay and not via the switch.

Thanks

[Greeks]

Crockett,

Simplest solution is just to fit some relays and forget about it. For the sake of about 15 quid in parts, and a couple of hours fiddling around you end up with an improved set-up which is capable of dealing with whatever upgrades you choose.

My knowledge of electrics dates back to a physics lesson when I was 12 ... during which I was probably busy sleeping or watching girls play hockey out of the window, but with the aid of a few of the friendly folk on here and some websites I managed to do it just this weekend.

Have a look at the following sites:
http://www.rowand.net/Shop/Tech/WiringHeadlightRelays.htm
http://www.the12volt.com/relays/relays.asp

It's got to be worth it  :)

[DaveKent]

or pm ellis (tr7nutter), he's put together a fact sheet for fitting a relay block and wiring for the big saloon lights

[Crockett]

[quote by=Greeks link=Blah.pl?b=2000,m=1157618047,s=3 date=1157665674]Simplest solution is just to fit some relays and forget about it. For the sake of about 15 quid in parts, and a couple of hours fiddling around you end up with an improved set-up which is capable of dealing with whatever upgrades you choose.
[/quote]

That's a fair point.

As I know something of electronics, I had already designed a circuit similar to the first link you sent. At this point I am thinking, I know what to do, I know how to do it - why don't I just get on with it?

So that's what I'm going to do :)

[Greeks]

well, don't be too hasty ... there's always time for a beer or seven first. Then it's best to leave until the next day  ;)

[Richard B]

I found that the weakest part of the lighting system is the column light switch.

I've had a couple fail due to corroded points that then cause over heating and the plastic melts (this is on MkII's, the Mk1 had a more robust set of switchgear).

I'd go for a relay set, the light switch is about £65 for a MkII.