• The Roadster Factory Recovery Fund - Friends, as you may have heard, The Roadster Factory, a respected British Car Parts business in PA, suffered a total loss in a fire on Christmas Day. Read about it, discuss or ask questions >> HERE. The Triumph Register of America is sponsoring a fund raiser to help TRF get back on their feet. If you can help, vist >> their GoFundMe page.
  • Hey there Guest!
    If you enjoy BCF and find our forum a useful resource, if you appreciate not having ads pop up all over the place and you want to ensure we can stay online - Please consider supporting with an "optional" low-cost annual subscription.
    **Upgrade Now**
    (PS: Subscribers don't see this UGLY banner)
Tips
Tips

Halogen head lights

Share this page

D

donandmax

Senior Member
Offline
Walmart sells halogen headlights for a little over 5 bucks each.I installed them in my midget (79) and they work well. Although I have never driven any distance with these on, I understand halogens should be used with a relay switch (easier on the on-off sw.) But I dont seem to have any problems at all using them with the stock set up. Is it that more expensive halogens draw more current and can cause switch failures ? Thus the need for a relay ?
Thanks
Don M
 
regularman

regularman

Yoda
Country flag
Offline
No the wattage draw should be the same. I think its fixed at like 55w and 65w or something for on road headlight bulbs. These bulbs just use a different type of filament and get more light out for the same power. I replaced one of mine with a halogen because it went bad and the other is just a normal sealed beam. I can't really tell a whole lot of difference. i thought of replacing them both with the fixed globe type where you use the replacement filament like the newer cars but they are expensive.
 
regularman

regularman

Yoda
Country flag
Offline
On the same thought I had trouble with headlight switches. The one that was in it when I bought the car burned up and then I bought two new ones that burned up after about 4-6 months each after use , so I replaced it with an industrial type switch with higher rated contacts. I think the problem was that I was driving during the winter months and worked a rotating shift where I would leave for work at either 6am or 6pm but either way it was driving in the dark all the time. I also had the original gen and running the lights, heater fan, wipers, etc kept the battery at a low level most of the time and this made the lights pull more amps at the lower voltage which might have added to the problem. Still at 40 bucks a pop, I wasn't going to keep putting in switches.
 
sparkydave

sparkydave

Jedi Knight
Country flag
Offline
The halogens shouldn't take any more current if they have the same wattage. I had a problem where the low beam contacts in my dimmer switch overheated and lost contact, so I put the relays in to overcome that problem. Not sure if it was just a lousy reproduction dimmer switch, but the relays helped in other ways too. Now when I turn the headlights on the dash lights aren't as dim, the wipers run faster, and the rest of the lights are brighter. I also took the opportunity to put fuses in the headlight circuit, which suprisingly didn't exist. Wires make good fuses, but tend to cause lots of other problems when they blow.
 
Jim_Gruber

Jim_Gruber

Yoda
Country flag
Offline
When I got Bugsy, driving at night could have been enhanced by holding a 2 D Cell Flashlight out the window. Headlights were so crappy driving could be described as dangerous. I installed headlight relays on Bugsy and it made a tremendous difference in headlight brightness. Try https://www.partsexpress.com. 12VDC DPDT Relay 20 Amp for $2.64 and a Relay Socket for $1.75 x 2. They also can provide a Wiring Diagram for Headlight Relays. Go to their site and Search under keyword Relay.

I mounted on right inside fender right by where wires come out of harness for headlights. I added fuses for safety sake and connected power directly to battery(Again Parts Express or Radio Shack). Cut and solder wiring, use Heatshrink as well. Parts Express sells Bulk Heatshrink all colors in 3' pieces as well. I have NFI in any of the suppliers mentioned.

This was a simple addition and interesting engineering exercise to do. Whole thing cost me < $15 including 20A fuses, fuseholders, and some wiring I had on the garage wall. This is a worthwhile project and really made a difference in driving at night.

Here is a useful link on Headlight Relays and Installing them.

https://www.danielsternlighting.com/tech/relays/relays.html
 
Jim_Gruber

Jim_Gruber

Yoda
Country flag
Offline
The closer you can get relays and powersource to the headlights the brighter the headlights will be. I on the other hand don't have a Bugeye that looks as nice and unmolested as your's. Relays really can go anywhere. You just need to be able to tap into the harness.
 
JPSmit

JPSmit

Moderator
Staff member
Silver
Country flag
Offline
I'm so not there yet but could someone please explain the concept of relays - I can't figure out how they would boost the voltage except by lowering resistance which - if you are installing near the light is at the end of the "hose" anyway - enquiring minds need to know

thanks all
 
sparkydave

sparkydave

Jedi Knight
Country flag
Offline
By removing the headlight load from the main wiring harness and supplying a separate set of power leads for the headlights, you don't get as much voltage drop through the main wiring harness, or through the old headlight and dimmer switches. Putting the relay near the headlights doesn't make much of a difference, other than it's more convenient to put the relays in where the left and right wires join together. There's a grounding lug near there too, which is convenient to connect the negative side of the relay coil.
 
leecreek

leecreek

Jedi Warrior
Country flag
Offline
I added a relay to get the headlight load off the old headlight switch. Working as intended.
 
P

piman

Darth Vader
Offline
Hello Kim,

"this made the lights pull more amps at the lower voltage"

electricity doesn't work like that. Lower voltage means lower current draw. The stated wattage is at rated voltage.

The point about relays and less voltage drop is actually due to the size of cables used to supply the load, if you use the same size cable the voltage drop will be the same unless the load and supply are very much closer, e.g. a battery very near the front of the car supplying head lights. Better, thought to go for larger cables. Certainly the switch will have less work to do but it was always rated for the full load anyway.

Alec
 
RickB

RickB

Yoda
Offline
This kind of fits in here, this morning I drove the Midget to work and it seemed like the left side wasn't as bright as it should be. Sure enough I pulled in to park & saw the two lights on the wall, the left side looked brown compared to the right.
Usually when a bulb goes it just goes, what's with this brown light? Anyone see this before?
 
RickB

RickB

Yoda
Offline
Thanks, I will look at that this afternoon.
 
JPSmit

JPSmit

Moderator
Staff member
Silver
Country flag
Offline
sparkydave said:
By removing the headlight load from the main wiring harness and supplying a separate set of power leads for the headlights, you don't get as much voltage drop through the main wiring harness, or through the old headlight and dimmer switches. Putting the relay near the headlights doesn't make much of a difference, other than it's more convenient to put the relays in where the left and right wires join together. There's a grounding lug near there too, which is convenient to connect the negative side of the relay coil.
Click to expand...

so in other words, a relay is simply a dedicated run of wires from the battery (fusebox) to the output (headlights) with presumably thicker wire - lower resistance - therefore brighter lights?
 
dklawson

dklawson

Yoda
Offline
The relays will also be "new" so their contact resistance will be lower than that of the in-dash switches. (Resulting in slightly higher voltage at the bulbs and less heating of switches).

I have a relay panel on the Mini to operate the high- and low-beams as well as the horn. The horn contact was what drove me to this. My horn wouldn't work at all. No matter how I cleaned the horn button contacts and all the horn ground wire connections the horn would just do an anemic grunt... I couldn't pass enough current. As soon as I installed the relay for the horn it worked perfectly.

I installed Halogens lamps and on the advice of a Canadian acquaintance of mine I installed relays for them as well. My goal was to take the high current off all the dash and dimmer switches. Relays are a lot less expensive.

Another inexpensive source for the automotive relays and sockets is BGMicro.com They sell the Bosch style ISO relays and sockets for prices close to those posted above.

Dan Masters (who is a member of this board) has a firm (https://www.advanceautowire.com/) that has lots of useful LBC wiring supplies and information... some of it specifically on this topic.
 
sparkydave

sparkydave

Jedi Knight
Country flag
Offline
JPSmit said:
so in other words, a relay is simply a dedicated run of wires from the battery (fusebox) to the output (headlights) with presumably thicker wire - lower resistance - therefore brighter lights?
Click to expand...

Almost; a relay is an electromechanical switch that uses a small amount of current to control a larger amount of current. For example, the starter solenoid is really just a big relay. The headlights are brighter by virtue of having a lower resistance path, and the other lights are brighter by virtue of not having a big voltage drop caused by the headlight current going through the main wiring harness.
 
P

piman

Darth Vader
Offline
Hello Dave

"and the other lights are brighter by virtue of not having a big voltage drop caused by the headlight current going through the main wiring harness."

Sorry Dave, but doesn't sound right? The voltage drop in one circuit doesn't affect the voltage in another.

Alec
 
RickB

RickB

Yoda
Offline
Unless you have a very large one that effects everything in the system. If the source is taxed then all the circuits will be effected.
 
sparkydave

sparkydave

Jedi Knight
Country flag
Offline
piman said:
Hello Dave

"and the other lights are brighter by virtue of not having a big voltage drop caused by the headlight current going through the main wiring harness."

Sorry Dave, but doesn't sound right? The voltage drop in one circuit doesn't affect the voltage in another.

Alec
Click to expand...

Certainly it does, since they share some of the same wiring. The main wiring harness has some resistance to it, because of a combination of light gauge wire and old bullet connectors that don't conduct as well as they used to. The more current you draw through the main wiring harness, the more the voltage drops for all the accessories running off of it. If you use the relays and a separate, heavier current path for the headlights, then there is significantly less current in the existing wiring harness, so less voltage drop and more voltage available for the rest of the accessories (i.e.: brighter lights).
 
Similar threads
Thread starter Title Forum Replies Date
Rob Glasgow Halogen Headlights Austin Healey 30
NutmegCT Halogen fog light bulbs Restoration & Tools 3
I PL 700 halogen wattage? Triumph 29
D Lucas PL700 headlamps w/ halogen bulbs? Triumph 16
SCguy Wedge Halogen H4 headlights for a TR8 Triumph 9
M Tripod or halogen MG 6
K TR2/3/3A Getting a cylinder head skimmed for flatness.... Triumph 1
K TR2/3/3A Update on the head gasket repair......something is not right/ Triumph 5
K TR2/3/3A New head gasket is installed.....did a compression check motor cold. Triumph 4
J Spitfire Payen Head Gasket -which way up ? Triumph 6
R TR6 Classic british car mechanic on Hilton Head SC Triumph 0
K TR2/3/3A The steel head stud washers? Triumph 7
K TR2/3/3A Applying the Permatex copper gasket spray to the head gasket? Triumph 6
S Spitfire Cyl head coolant hose fitting Triumph 1
B TR6 Milling the head Triumph 5
sim 948 aluminum head gasket Spridgets 2
K TR2/3/3A Retorquing the Cylinder Head after the initial torquing.? Triumph 23
S TR2/3/3A Rebuilding a cylinder head Triumph 10
petnatcar Cylinder Head Nuts - Tightening Sequence Austin Healey 2
tahoe healey "Convertible" vs "Drop Head Coupe" Austin Healey 8
K TR2/3/3A head gasket repair wire Randall Triumph 1
K TR2/3/3A Checking a cylinder head with a straight edge to see if it's warped? Triumph 22
K TR2/3/3A Cylinder Head Bolt question.... Triumph 3
Celtic 77 MGB Mystery cylinder head attachment. MG 4
tinman58 TR2/3/3A Head Gasket Triumph 15
K TR2/3/3A Cylinder head removal and valve adjustment Triumph 2
K TR2/3/3A Update on the blown head gasket Triumph 33
K TR2/3/3A Bad news...blown head gasket??? Triumph 15
F TR2/3/3A head light buckets Triumph 3
D TR2/3/3A cylinder head oil plug bolt size Triumph 6
R Big Healey 100 Head Austin Healey 4
nichola TR6 Hot spot on cylinder head - 1973 TR6 Triumph 2
R For Sale 100 engine block w/head Austin Healey Classifieds 3
B Surprise screw head Restoration & Tools 0
D TR6 Gp 2 cam, head shaved ,shorter pushrods, with a rough idle Triumph 10
K TR2/3/3A Who sells steering wheel control head "Allen head'' grub screws? Triumph 5
B Head Re-Torque Austin Healey 8
AUSMHLY Reduced-Shank Cylinder Head Studs Austin Healey 0
AUSMHLY Cylinder Head Studs Austin Healey 3
AUSMHLY Cylinder Head Input/Exhaust Circlip/Split pin Austin Healey 3
AUSMHLY Engine Flush After Head Gasket Leak Austin Healey 19
KVH General Tech Rusted Cylinder Head Freeze Plug--WOW Triumph 16
KVH General Tech Head Gasket Sealant Triumph 4
AUSMHLY BJ8 Cylinder Head Installation Austin Healey 6
KVH General Tech ARP Head Studs/Liner Protrusion Triumph 10
healeynut For Sale 100/4 block and head Austin Healey Classifieds 1
K TR2/3/3A Inside the horn and turn signal control head. Triumph 3
T TR2/3/3A Water pumps/head cooling Triumph 22
T TR2/3/3A cylinder head ,valves and springs Triumph 0
KLUTZ Wedge Adding Blue Devil head gasket sealer Triumph 4

Similar threads

Top