Update headlights

MY 78 B was owned by the P.O. for over 14 years before I bought it he told me he had never done any maintenance work on the car, other than fixed things that where broken. So I estimate my headlights are at least 10 years old. I know that overtime lights can dim and with the lucas alternator I can't expect much out of them. Should I update them..? or do H4 swap..?

Just put in new sealed beam lights and add some relays to them, you'll be amazed at the difference.

So just a regular 30A relay will do..? Is there a diagram on how to...? I hate to chop anything on this car right now it is chop free!

Limey has a great relay kit that is ready to install.

Limey's relay kit and H4 headlights. The best $80 I've spent on my B's.

http://www.bits4brits.net/Relays.html

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=330356834394&viewitem=&sspagename=STRK%3AMEWAX%3AIT

Don't just put in seal beams, at least put in halogen seal beams.

For H4 units take a took at:
Susquehanna http://www.rallylights.com/Hella_7_inch_Round_H4_%20Headlamps.aspx or
Dan Stern http://www.danielsternlighting.com/products/products.html

x2 on doing at least halogen sealed beams

BTW all headlamps, sealed beam and H4 bulb do dim over time. Thermionic emmission cause metal ions to come off the filament. They condense on the envelope causing eventual dimming of the bulb.

Depends on your needs really. In good order a standard set of sealed beams are quite good. Halogens are brighter. First thing I would do is ensure all the grounds, switches and connectors are making good contact with no resistance. Often just cleaning things up improves the lighting tremendously. Relays can brighten the lamps, but if you don't address the rest of the system first then you're just putting a band-aid on a flesh wound.

http://www.victoriabritish.com/icatalog/mg/full.aspx?Page=33


I put on this wiring harness and halogen lights and what a difference!! Now it's only $19 at $30 it was a great deal.

OK, I will ask a stupid question.

Why do you need to add relays when you change out the headlights?

You don't [i]need[i] to add them....but you may want to. You'll get more current to the lamps since the relay bypasses the switch and several yards of wire. It also takes the heavy current load off the switch, making it less prone to failure...

Joe,

To clarify what you are saying, you still would use the same headlight switch?

I am still not totally clear on adding this extra relay.

So does the power supply come from the fuse box, or as the ad from Victoria British says, directly from the battery?

Yes, you use the same switch. Look at it this way.....

Right now your headlamp switch carries all the current from the battery, through the switch, and on to the headlamps. Headlamps require quite a bit of current.

If you install a relay, the current to the headlamps goes from the battery, through the relay and on to the headlamps. The switch only carries enough current to switch on the relay.

You can leave it as is, but you'll probably have brighter lights using the relay. If you plan to use high powered lamps, a relay is more important - since the switch wasn't intended to carry that much current.

...now I understand...thank you

Sealed beam lamps come in halogen and standard tungsten versions. Halogen has become the standard in modern cars (Xenon, etc in new higher end cars) but you can still buy tungsten lamps. I run them on three cars including my daily driver.

Well, they're quaint little cars! ;) I'm certainly seeing fewer and fewer tungsten bulbs in big chain parts houses, but the "real" auto parts stores still have them, and you can mail order any type you wish also. I have a cabinet of Lucas sealed beam tungsten lamps that are actually quite bright, relatively speaking.

A drawing sometimes makes things a bit clearer. If you do not understand automotive electrical systems very well, and especially the ones in use in MGBs, I highly recommend you think about purchasing Rick Astley's very good book on just this topic, "MGB Electrical Systems" You can find it pretty easily at LBCarCo, Moss, Vicky Brit, and Amazon. You may find some other useful info at this site as well, http://www.cibolas7.net/30105.html The advice above is basically all good, and my best advice is to go slowly with electrical stuff, especially if it is something new to you.

Also, just be aware that there is more than one type of sealed beam Halogen lamp out there as well. There are regular units and then there are those which produce about 30% more light. Altho not as bright as some of the separate halogen capsule/reflector European lamps, they still produce visibly more light than just ordinary halogen sealed beam lamps, and quite a bit more than ordinary tungsten lamps. Typically, they are offered alongside regular Halogen sealed beam units as an upgrade at most parts houses and some discounters like Walmart. GE's version is called NightHawk, and Sylvania actually has two ~ Xtravision and Silverstar. All come in standard 7" round configuration and directly replace the old tungsten units (altho you'd be smart, as the guys have said, to use heavier wiring and relays with these). One relay for high beams, one for low.

Limey's kit is probably your best bet for an MGB specific fix.

I had dismal lights even with the halogens and wiring them off the starter with relays made them at least twice as bright and the amps are not going thru the switch. Now if only I could brighten up the dash lights!!

I bolted mine to the starter.

what guage wire should be used from the relays to the headlights and from the battery to the relay.....and i assume that the wiring from the switch to the relay can remain as the same guage.

thanks

You don't need to run a wire from the relays back to the battery. Wires from the relays to the battery wire stud on the starter are sufficient. The wire from the dip & headlight switches are sufficient to operate the relays.

If you are using the standard 65/55 watt headlamps, either halogen or tungsten, the following configurations will have no more than a 2% drop in voltage to the headlamps. The drop is splt equally between the starter/relay connection and the relay /lamp connection.

A single wire routed from the starter to each relay in turn: < 4 feet, 8AWG; 5-7 feet, 6AWG; 8-12 feet, 4AWG
A wire routed from each relay to the starter: < 3 feet, 12AWG; 4-5 feet, 10AWG; 6-9 feet, 8 AWG; 10-14 feet, 6AWG
A single wire routed from the relay to both high beams or from the relay to both low beams: < 3 feet, 12AWG; 4-5 feet, 10AWG; 6-9 feet, 8 AWG; 10-14 feet, 6AWG
A total of 4 wires from the relays to the headlamps: < 4 feet, 14AWG; 5-7 feet 12 AWG; 8-11 feet, 10 AWG

If your wattages are higher the distances you can run with a certain gauge will be reduced.

Visit Daniel Stern's lighting website ( I think it is http://www.danielsternlighting.com ) - there are great diagrams there.

#1 - put in relays. That removes almost all of the current flow through the switch
#2 - get good headlamps. I recommend Cibie. Stern sells them if no one near you does. How much do they cost? I don't know, but they saved my car from a deer this summer. I figure that makes them worth several thousands dollars. (But I think a set will run somewhere around $100).
#3 - a Lucas alternator will have no problem powering the headlamps. Except right at idle, a 16ACR alternator should be able to hold the voltage at 14v.

thank you.

Has anyone had problewm with the converation, when I turn on my headlights my alt drops .30 volts output, from 12.1isk to 11.8ish at idle. I have a gm alt on. I am using the 12v100/90w super plazma xenon bulb?